The Costco Arbitrage Opportunity
Costco sells branded products in bulk at prices below typical retail. For Amazon sellers, this creates an arbitrage opportunity — buy at Costco's bulk prices, split into individual units, and sell on Amazon at a higher per-unit price. The Costco membership costs around forty pounds per year, which can pay for itself with a single good sourcing trip.
What Sells Well from Costco
The best categories for Costco-to-Amazon arbitrage tend to be branded health and beauty products, multipacks of consumables, premium food and drink items, electronics accessories, and seasonal goods. Costco rotates its stock regularly and brings in limited-time products that can create short-term arbitrage windows.
Look for items where the per-unit cost at Costco is significantly lower than the individual selling price on Amazon. Multipacks are particularly interesting — a pack of six items at Costco might be worth splitting into six individual Amazon listings.
Checking Profitability
Before buying anything, scan the barcode with the Amazon Seller app. Check the selling price, sales rank, and number of competing sellers. Then calculate your actual profit after Amazon referral fees, FBA fees, and any prep costs. Remember to include your Costco membership fee in your overall cost calculations for the year.
Be cautious with grocery items — they require category approval on Amazon and have strict expiry date requirements. Health and beauty products may also have brand restrictions.
The Membership Advantage
One advantage of Costco sourcing is that the membership creates a small barrier to entry. Not every reseller has a membership, which can mean less competition on some products compared to items sourced from open-to-all retailers like B&M or Tesco.
The Executive membership, which costs more but offers cashback on purchases, can make sense if you plan to source regularly. The cashback effectively reduces your cost of goods, improving margins on every purchase.
Limitations to Consider
Costco has a limited number of UK locations, so this strategy only works if you live within reasonable driving distance of a store. Stock varies between locations and changes frequently, so what you find on one visit may not be there the next. You also cannot order online for most products at the same prices you find in store.
As with all retail arbitrage, the scale is limited by what is physically available. Costco sourcing works best as one element of a diversified sourcing strategy rather than your sole stock source.