K-Beauty Cosrx vs Beauty of Joseon vs Skin1004: US vs Korea Cross-Market Guide 2026

Updated: September 2026

Cosrx, Beauty of Joseon, and Skin1004 have quietly become the most-searched K-beauty heroes in the US, showing up in TikTok routines, Sephora endcaps, and Amazon Prime carts. Through most of 2024, ordering direct from Korea via Olive Young Global, YesStyle, or Stylevana was the obvious answer for US buyers because the shelf gap was 30 to 50 percent. In 2026 the picture has flipped. Here is what actually holds up now.

The verdict: the arbitrage is largely closed

Through most of 2024 the cross-market K-beauty arbitrage was real. Korean sites listed Cosrx Advanced Snail 96 Mucin Power Essence, Beauty of Joseon Relief Sun, and Skin1004 Madagascar Centella Toning Toner at 30 to 50 percent below Amazon US shelf price, and the freight was cheap enough that even single-bottle orders penciled out. As of 2026 that gap has largely closed. Three things happened in 2025 and 2026:

1. Amazon US caught up on the K-beauty catalog. Cosrx, Beauty of Joseon, and Skin1004 all have official brand storefronts on Amazon US in 2026, with Prime shipping, Prime returns, and pricing that runs at parity or better on the standard hero SKUs. Ulta and Sephora US both expanded K-beauty stocking through 2025 with in-store availability plus online.
2. Tariff and FX movements narrowed the wholesale edge. 2025 to 2026 US tariff policy shifts and USD-KRW rate movement compressed the price gap between what Korean sites list and what US retailers charge. The Korean shelf price minus VAT minus international handling no longer sits materially below Amazon US on the standard SKUs.
3. International freight and 1 to 3 week wait eat what remains. DHL Express from Olive Young Global runs USD 8 to 25 depending on cart weight; economy is slower and prone to summer heat damage on sunscreen. Once shipping and time value are priced in, the direct-from-Korea math on a single-item order is nil or negative.

The result: for the standard hero-SKU order in 2026, Amazon US, iHerb, Ulta, and Sephora US typically win on money-and-time combined. The narrow cases where direct-from-Korea still works are noted below. For every other US routine buyer, the ShopBack path replaces the arbitrage: compare cashback rates across Amazon US, iHerb, Ulta, and Sephora US on the same SKU, activate ShopBack via the browser extension before checkout, buy from whichever merchant shows the best net price.

What replaced K-beauty arbitrage: the ShopBack path

Use ShopBack to compare cashback rates across US beauty retailers on the same hero SKU before each order. Check ShopBack for the current published rate on iHerb, Ulta, Sephora US, and other participating US beauty merchants. Activate ShopBack via the browser extension on desktop Chrome or Edge, or the ShopBack in-app browser on iOS and Android, so tracking fires before checkout. Start every K-beauty restock at ShopBack instead of going directly to the retailer, so the cashback layer stacks on top of whatever sale or loyalty pricing the merchant is already running (Sephora Beauty Insider, Ultamate Rewards, iHerb Rewards). Run this playbook once and the recurring K-beauty spend earns a consistent US cashback rate without the international shipping, without the wait, and without the authenticity risk. Amazon US is not a US cashback partner, so route Amazon-only orders through the fastest Prime option and take the credit-card reward as the sole return on that leg.

Earn cashback on beauty retailers on ShopBack Takes 2 minutes to sign up. No promo codes needed.

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The three hero SKUs, side by side

The three products in this comparison are the most-searched K-beauty items in the US in 2026, based on brand-radar and marketplace data, and each represents a different price tier and use case.

Cosrx Advanced Snail 96 Mucin Power Essence (100ml): a snail-secretion filtrate essence used as a barrier-repair and hydration step after cleansing. The single most-recommended K-beauty product globally, in continuous production since 2014, safe for most skin types including sensitive.

Beauty of Joseon Relief Sun Rice Probiotics SPF50+ (50ml): a chemical sunscreen with rice extract and probiotics, widely regarded as one of the best chemical sunscreens on the global market for daily wear. A US buyer favourite because it is genuinely elegant, affordable, and effective at true SPF50+ protection.

Skin1004 Madagascar Centella Toning Toner (210ml): a centella asiatica extract toner used as a hydration and soothing step, popular with acne-prone and reactive skin. Skin1004 has broken into the US market fast in 2024 to 2026 via Amazon and Ulta expansion.

All three are widely available across Amazon US, iHerb, Ulta, Sephora US, Olive Young Global, Stylevana, and YesStyle. Prices below are typical retail brackets observed as of September 2026 and shift with promotions, batch, tariff policy, and FX. The 2024-era 30 to 50 percent Korea-to-US gap has narrowed materially through 2025 to 2026 as Amazon US, Ulta, and Sephora US expanded K-beauty distribution and tariff/FX moves compressed the wholesale margin.

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The numbers, channel by channel

Product	Amazon US (typical)	iHerb US (typical)	Olive Young Global (before ship)	Stylevana / YesStyle (before ship)	Sephora US / Ulta
Cosrx Advanced Snail 96 Mucin Essence 100ml	USD 17 to 22	USD 16 to 20	USD 12 to 15	USD 11 to 14	USD 22 to 25 (Sephora / Ulta, when stocked)
Beauty of Joseon Relief Sun SPF50+ 50ml	USD 15 to 19	USD 14 to 18	USD 11 to 14	USD 10 to 13	USD 16 to 20 (Sephora / Ulta, select stores)
Skin1004 Madagascar Centella Toning Toner 210ml	USD 20 to 26	USD 19 to 24	USD 15 to 19	USD 14 to 18	USD 22 to 26 (Ulta, when stocked)

Ranges reflect typical listings in September 2026 and shift with promotions, batch, tariff policy, and FX. Korean-site prices are shown before international shipping; shipping to a US address is DHL Express at USD 8 to 25 (Olive Young Global) or economy at USD 5 to 15 (Stylevana / YesStyle). Free-shipping thresholds are approximately USD 60 (Olive Young Global) and USD 60 to 75 (Stylevana / YesStyle) as of September 2026.

The 2026 math on a single-product order: a solo bottle of Cosrx Snail Essence at USD 14 on Olive Young Global plus USD 12 shipping is USD 26, compared to USD 19 on Amazon US with Prime or roughly USD 17 on iHerb. Amazon or iHerb wins. Now stack three products: Cosrx + Beauty of Joseon + Skin1004 direct from Korea at USD 14 + USD 13 + USD 17 = USD 44, still short of the USD 60 free-shipping threshold, so add another SKU or absorb the USD 12 shipping to land at USD 56. Same basket on Amazon US: roughly USD 19 + USD 17 + USD 22 = USD 58. Direct-from-Korea now saves USD 2 (roughly 3 percent) on a three-item basket, with a 1 to 3 week wait as the trade-off. Compared to 2024 the gap has collapsed. Add ShopBack cashback on iHerb, Ulta, or Sephora US and the direct-from-Korea math turns negative on most standard-SKU baskets.

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Use case, use case

Buyer profile	Recommended channel in 2026	Why
First-time K-beauty buyer trying one product	Amazon US (official brand storefront), Ulta, or Sephora US	Prime shipping, easy returns, authenticity verified; ShopBack cashback on Ulta and Sephora US legs
Established K-beauty routine, restocking 3 items	Amazon US or Ulta with ShopBack	2024-style Olive Young Global edge has collapsed; ShopBack cashback on Ulta beats direct-from-Korea net in 2026 on standard SKUs
Bulk buyer or large-size SKU seeker (e.g. Skin1004 400ml water-fit serum)	Olive Young Global	Where Amazon US does not stock the size, direct-from-Korea remains the only path; bulk baskets still clear economics
Buying sunscreen only, high frequency of use	iHerb or Ulta with ShopBack	Cold-chain matters for SPF; iHerb ships within US from bonded warehouse; ShopBack cashback on iHerb
Buyer already ordering supplements or vitamins	iHerb with ShopBack	Consolidate cart, one shipment, iHerb Rewards plus ShopBack cashback
Sephora Beauty Insider Rouge member	Sephora US with ShopBack when Cosrx or Beauty of Joseon is stocked	Points earn on prestige tiers, birthday gift, Rouge sale in April and November stacks with cashback via ShopBack
Ulta Diamond member	Ulta with ShopBack for Skin1004 and Cosrx	21 Days of Beauty discounts, Diamond tier 1.5x points, ShopBack cashback stacks
Traveling to Seoul in 2026	Olive Young Myeongdong or Gangnam flagship in person	10 percent VAT refund with passport (KRW 30,000 minimum per receipt); combine with in-store staff recommendations and full brand lineup
Gifting K-beauty to a friend	Amazon US or Sephora US	Gift receipt, returnability, faster arrival for occasion timing
Reactive or acne-prone skin, first-time Skin1004	Amazon US via official Skin1004 storefront or Ulta	Return policy matters when testing tolerance; Amazon return within 30 days is smoother than international
Hunting a US out-of-stock hero SKU during peak sale weeks	Olive Young Global or Stylevana	The one remaining case where direct-from-Korea reliably beats the US channel: US inventory has cleared and you need it now

The 2026 pattern: on standard hero SKUs Amazon US, iHerb, Ulta, and Sephora US with ShopBack now beat direct-from-Korea on money-and-time combined. Direct-from-Korea remains the answer for large-size SKUs, Korean-only bundles, and US out-of-stock hero items during peak weeks.

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What US buyers routinely get wrong

Assuming all Amazon third-party K-beauty is authentic. It is not. Cosrx, Beauty of Joseon, and Skin1004 all have official brand storefronts on Amazon US. Buying from third-party sellers even at a lower price runs a real risk of receiving expired, diverted, or counterfeit product. Check "Sold by" against the brand's official storefront name (Cosrx Official, Beauty of Joseon Official, Skin1004 Official) before ordering.

Ordering sunscreen through slow economy shipping in summer. Beauty of Joseon Relief Sun contains sensitive filters and probiotic ferments. A 21 day container-ship transit through hot ports and warehouses degrades the formula. If sunscreen is the priority SKU, buy from Amazon US or iHerb (both maintain climate-controlled US-based warehouses) or Olive Young Global DHL Express, not standard shipping.

Not clearing the free-shipping threshold on Korean sites. The whole economic case for direct-from-Korea depends on hitting the USD 60 to 75 threshold that unlocks free shipping. A USD 12 solo essence with USD 15 shipping is worse economics than Amazon Prime. Stack three products, clear the threshold, and the direct-from-Korea math works.

Buying Cosrx Snail Essence and Beauty of Joseon Relief Sun in the same trip to Korea and ignoring the VAT refund paperwork. If you are physically in Korea, always ask for the tax-refund receipt at Olive Young checkout with your passport. The 10 percent refund is real cash back at the airport kiosk on departure, subject to the KRW 30,000 minimum per receipt.

Assuming Sephora US has the full K-beauty lineup. Sephora US carries a curated selection (Cosrx, Beauty of Joseon, Anua, Round Lab in select stores, Torriden in some) but not full catalog depth. Ulta has broader K-beauty coverage on mass tiers (Cosrx, Skin1004, Some By Mi, Cerave dupes, Innisfree). For specialty SKUs beyond the hero list, Korean sites remain the only source.

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What this means in practice

A US buyer with a stable Cosrx snail plus Beauty of Joseon sunscreen plus Skin1004 toner routine, restocking every 8 to 12 weeks, should now default to Amazon US or Ulta with ShopBack for standard SKUs. Basket cost approximately USD 55 to 65 with Prime plus a couple percent back on the Ulta or Sephora legs via ShopBack, versus USD 55 to 60 on Olive Young Global including shipping with a 1 to 3 week wait. The 2024-era USD 15 to 25 direct-from-Korea saving on this basket has largely disappeared. Use ShopBack to compare cashback rates on Ulta and Sephora US on the same SKU before every restock; check ShopBack when the retailer is running a promotion so the cashback layer stacks on top.

A US buyer trying K-beauty for the first time should buy Cosrx or Beauty of Joseon from Amazon US via the official brand storefront or from Ulta. Prime shipping, return within 30 days if the formula does not agree, and full authenticity confidence via the official storefront. The 2026 pricing gap versus Korean sites is small enough that the wait and return-risk trade is not worth it.

A Sephora Rouge member should watch for the April and November Beauty Insider sales and stack the Rouge discount (typically 20 percent off) on Cosrx or Beauty of Joseon when in stock, plus cashback through ShopBack. Activate ShopBack via the browser extension before Sephora checkout so the cashback layer tracks on top of the Rouge tier discount.

A US buyer traveling to Seoul in 2026 should hit Olive Young Myeongdong or Gangnam flagship, present passport at checkout for tax-free processing, and clear KRW 30,000 minimum per receipt. Expect roughly 15 to 30 percent savings versus US retail on the same SKUs (narrower than the 2024 gap after FX and tariff moves) before considering the trip cost. Do not fly to Korea for K-beauty alone; bolt shopping onto a food, culture, and design trip.

A buyer chasing a specific large-size SKU (Skin1004 400ml water-fit sun serum, hyalu-cica ampoule bundles, Korean-only value packs) or hitting a US out-of-stock moment during Black Friday, Cyber Monday, or a peak Ulta 21 Days sale should still go to Olive Young Global or Stylevana. That is the narrow 2026 window where direct-from-Korea remains materially cheaper or the only channel that stocks the SKU.

ShopBack offers cashback on selected beauty retailers in the US market; participating merchants and published rates change over time and by market, so check current merchant pages on ShopBack US before ordering. Amazon US is not currently a US cashback partner. Korean sites (Olive Young Global, Stylevana, YesStyle) are typically not directly integrated on ShopBack US, though their own coupon codes stack cleanly with Korean-site loyalty programs. Use ShopBack to compare cashback rates across Ulta, Sephora US, and iHerb before every K-beauty order, and start every restock at ShopBack so the tracking click is captured.

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When this does NOT apply

• Prescription-strength or high-active skincare. Anything above cosmetic-grade actives (prescription tretinoin, medical-grade peels) is outside the scope of consumer K-beauty channels; buy through licensed US dermatology channels.
• Buying for someone with unknown skin sensitivity. Gift a Sephora or Ulta gift card and let the recipient choose in person; long-transit sunscreen or actives from Korea is a bad gift for a reactive skin type.
• Emergency restock, need this week. Amazon US Prime or Ulta store pickup, full stop. Korean shipping is 3 to 21 days depending on tier.
• You do not have a credit card with strong international purchase protection. Charge-back rights on international online orders matter if a package arrives damaged, expired, or authenticity-suspect.
• You already earn 5x+ points on Amazon on your primary card. The points economics may narrow the case for Korean direct enough that Amazon Prime is the pragmatic default.
• You live outside major US metros with reliable DHL delivery. Rural US addresses see Korean-site shipping timelines drift longer; the Amazon advantage widens.

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Frequently asked questions

Is the cross-market K-beauty arbitrage still worth it in 2026?

Mostly not. Through most of 2024, buying via YesStyle, Stylevana, or Olive Young Global saved US shoppers 30 to 50 percent versus Amazon US on Cosrx, Beauty of Joseon, and Skin1004 hero SKUs. As of 2026 that gap has largely closed. Amazon US now stocks these brands at parity or better via official brand storefronts, tariff and USD-KRW rate movements since late 2024 eroded the wholesale edge, and international freight plus 1 to 3 week wait eats what remains. Narrow cases where direct-from-Korea still works: large-size SKUs Amazon US does not stock, US out-of-stock hero items during peak sale weeks, and multi-item Korean-only baskets clearing free-shipping thresholds. Use ShopBack to compare cashback rates across Amazon US, iHerb, Ulta, and Sephora US before ordering.

How much is Beauty of Joseon Relief Sun in the US in 2026?

Beauty of Joseon Relief Sun Rice Probiotics SPF50+ 50ml sits around USD 15 to 19 on Amazon US and iHerb as of September 2026, with occasional multi-pack promotions bringing per-bottle cost to roughly USD 12 to 14. On Olive Young Global and Stylevana it lists closer to USD 11 to 14 before shipping; once you add USD 8 to 15 international shipping and 1 to 3 week wait, the direct-from-Korea edge on a single tube is nil or negative. Sephora US and Ulta carry Beauty of Joseon at the higher end of the Amazon range with ShopBack cashback available on the Sephora and Ulta legs.

Where should I buy Skin1004 Madagascar Centella Toning Toner in the US in 2026?

Skin1004 Madagascar Centella Toning Toner 210ml sits around USD 20 to 26 on Amazon US and iHerb as of September 2026, roughly USD 15 to 19 on Olive Young Global and Stylevana before shipping. Skin1004 is widely available on Amazon US via the brand's official storefront and at Ulta. On the standard 210ml SKU the arbitrage does not clear once shipping and wait are factored in. Direct-from-Korea still wins in 2026 on the larger Skin1004 water-fit sun serum sizes and Korean-only bundles Amazon US does not stock. Use ShopBack to compare cashback across Ulta and iHerb before checkout.

Is Olive Young Global legit and how long does US shipping take?

Yes, Olive Young Global is the official international arm of CJ Olive Young, Korea's largest health and beauty chain. All products ship from Korea and are authentic direct from brand. US shipping is DHL Express (paid) or standard economy (free above roughly USD 60 as of August 2026); DHL runs 3 to 6 business days to most US metros, standard runs 8 to 21 days.

Is Stylevana authentic K-beauty?

Stylevana is a Hong Kong headquartered retailer sourcing from Korean brand distributors. Authenticity is generally good on major brands but has been mixed on rarer SKUs and older batches. Best practice: check batch dates on arrival, use a credit card that supports chargeback, and stick to hero SKUs from established brands. Prices are the lowest of any legitimate retailer; shipping is slower than Olive Young Global.

Does Amazon US sell authentic Cosrx?

Yes, Cosrx sells directly on Amazon US via the official brand storefront. Buying from the official storefront ensures authenticity, Prime shipping, and Amazon's return policy. Third-party sellers listing Cosrx on Amazon US have historically had mixed authenticity outcomes; check the seller name against the official storefront before adding to cart.

What is Olive Young in Korea and why do prices differ?

Olive Young is Korea's dominant health and beauty chain, comparable to Ulta in the US or Watsons in Asia. Olive Young Global (the international shipping arm) prices in USD near Korea's in-store retail minus VAT plus a small international handling premium. Amazon US and Sephora US layer distributor margin and US retail markup on top, which is why the same product runs 25 to 45 percent higher stateside.

Do I get the Korea VAT refund if I order online from the US?

No. Korea's 10 percent VAT refund is available only to foreign tourists making qualifying purchases in-store in Korea with passport at point of sale. Online international orders from Olive Young Global and Stylevana are already shipped tax-exclusive.

How do I stack cashback on K-beauty purchases in the US?

For US buyers, ShopBack partners with beauty retailers including Sephora US, Ulta, and a rotating set of specialty e-tailers; check current published rates on each merchant page before purchase. Amazon US is not a ShopBack partner in the US market. iHerb and Stylevana run their own coupon and loyalty programs. Olive Young Global runs first-order coupons and periodic promotions timed to Korean shopping events.

Should I travel to Seoul just to buy K-beauty?

Rarely worth it for K-beauty alone. Round-trip US to Seoul economy runs USD 900 to 1,600, plus hotel. Total trip cost for a typical 4 to 5 night visit far exceeds K-beauty savings versus online US pricing. Bolt K-beauty shopping onto a trip you were taking anyway.

Does ShopBack cashback apply when I buy Cosrx or Beauty of Joseon at Sephora US or Ulta instead of ordering from Korea?

Yes on the US retailer leg. ShopBack cashback tracks on eligible Sephora US and Ulta Beauty orders when the click starts from the ShopBack merchant page inside the ShopBack browser extension for desktop Chrome or Edge, or the ShopBack in-app browser on iOS and Android. Sephora US now stocks Beauty of Joseon and Cosrx in select stores and online, and Ulta carries Cosrx. Skin1004 has thinner US retailer distribution and remains best-priced direct from Korea. For a US-based K-beauty top-up between Korean shipments, activation at Sephora or Ulta takes about 10 seconds and cashback posts to your ShopBack account separately from Beauty Insider or Ultamate Rewards points. Verify current published cashback rates on each merchant page before ordering.

How much cashback do you get on K-beauty orders at Sephora US, Ulta, or iHerb?

Cashback rates on ShopBack for Sephora US, Ulta Beauty, and iHerb rotate through the year. Historical rates on US beauty retailers have sat in the 3 to 8 percent range across the catalog. Check the current published rate on each merchant page at shopback.com before checkout on a K-beauty order. Amazon US is not currently a ShopBack US partner.

How many days does K-beauty cashback take to process on a US retailer order?

Cashback tracks in your ShopBack wallet within a few hours of checkout as pending, and confirms after the retailer's return window closes. Sephora, Ulta, and iHerb return windows are 30 to 60 days. Plan on 30 to 90 days from checkout to withdrawable cashback on a typical K-beauty restock at a US retailer.

When do prices drop on K-beauty at US retailers?

Amazon Prime Day (October 2026 second-day event) and Cyber Week are the strongest US windows for Cosrx and Beauty of Joseon markdowns. Sephora Beauty Insider Sale (April, November) covers Beauty of Joseon and select Cosrx SKUs at 10 to 20 percent off by tier. Ulta 21 Days of Beauty in September and March rotates Cosrx and Round Lab daily deals. Korean-site promotions time to Chuseok (September to October) and Korean Black Friday.

Is Amazon US cheaper than Sephora US for Cosrx Snail Essence in 2026?

Yes, typically. Cosrx Advanced Snail 96 Mucin Power Essence 100ml runs USD 17 to 22 on Amazon US via the official Cosrx storefront in 2026, versus USD 22 to 25 at Sephora US or Ulta on the same SKU. Amazon Prime shipping and the official brand storefront make it the pragmatic pick on standard SKUs. ShopBack cashback is available on Sephora US and Ulta but not Amazon US, so the Amazon savings on this specific SKU do not stack with ShopBack.

Does ShopBack cashback stack with credit card rewards on iHerb K-beauty orders?

Yes. ShopBack cashback is tracked via referral cookie set at click-through, and iHerb Rewards accrue separately on the iHerb account. 2 to 3 percent cash-back credit cards layer on top since they operate on the card ledger. A single iHerb K-beauty basket with Beauty of Joseon Relief Sun, Cosrx Snail Essence, and vitamin restocks can carry three independent reward stacks in the same transaction.

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Key takeaways

• The 2024-era 30 to 50 percent cross-market K-beauty arbitrage has largely closed in 2026
• Amazon US, Ulta, and Sephora US now stock Cosrx, Beauty of Joseon, and Skin1004 hero SKUs at parity or better with Korean sites after shipping
• Tariff and USD-KRW rate movements in 2025 to 2026 compressed the wholesale margin further
• Narrow cases where direct-from-Korea still works: large-size SKUs, US out-of-stock hero items in peak weeks, multi-item Korean-only baskets clearing free shipping
• Amazon US via official brand storefronts is authentic and the fastest; Ulta and Sephora carry a curated K-beauty selection with ShopBack cashback on the Ulta and Sephora legs
• iHerb is the best choice for sunscreen (climate-controlled US warehouse) and for consolidating supplement orders; ShopBack cashback available on iHerb
• Use ShopBack to compare cashback rates across Ulta, Sephora US, and iHerb on the same SKU before every K-beauty order
• The Korea VAT refund only applies to in-person Korea purchases; online orders ship tax-exclusive already
• Traveling to Seoul just for K-beauty rarely pays back; combine with a broader trip if going
• ShopBack cashback rates and participating US beauty retailers change; verify on the merchant page before purchase

Restocking your K-beauty routine? Earn cashback on beauty retailers on ShopBack. Takes 2 minutes to sign up. No promo codes needed.

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Disclaimer

The views and recommendations expressed in this article are those of the author.

Retail prices, shipping fees, VAT refund schemes, and merchant partnerships are subject to change. Please verify pricing and shipping directly with Amazon US, iHerb, Olive Young Global, Stylevana, YesStyle, Sephora US, Ulta, and any relevant tax authority before making a purchase decision.

This article is intended for general informational purposes only and should not be considered professional financial, tax, or purchasing advice.