Every "which selling platform is cheapest" article gives you the headline percentages — Amazon's 15%, Etsy's 6.5%, eBay's 13.6% — and stops there. None of those numbers is the whole fee, and none of them is directly comparable to the others on its own. Here's one real sale run through all four platforms' actual published formulas, side by side.
The same sale, four platforms
A $50 item with $5 buyer-paid shipping ($55 total), sold in Amazon's "most categories" tier as a Small Standard-Size item, on Shopify's Basic plan with Shopify Payments, and within eBay's free monthly listing allowance:
| Platform | Fee lines | Total fees | You keep | Margin |
|---|---|---|---|---|
| Shopify (Basic) | Payment processing: 2.9% + $0.30 | $1.90 | $53.10 | 96.55% |
| Etsy | Listing $0.20 + transaction 6.5% + processing (3% + $0.25) | $5.68 | $49.32 | 89.67% |
| eBay | Final value fee: 13.6% + $0.40 per order | $7.88 | $47.12 | 85.67% |
| Amazon FBA | Referral fee 15% + fulfillment fee (incl. surcharge) | $11.75 | $43.25 | 78.64% |
Ranked by margin percentage alone, Shopify wins by a wide margin and Amazon FBA comes in last. That ranking is real — but reading it as "Shopify is the cheapest platform, full stop" misses two things that don't show up in a fee-only table.
Why this isn't an apples-to-apples "cheapest" verdict
Amazon's fee includes a service the other three don't. Amazon's fulfillment fee ($3.50 of the $11.75 above) pays Amazon to physically pick, pack, and ship your item. On Etsy, Shopify, and eBay, that same work still has to happen — you're just paying for boxes, labels, and postage yourself, out-of-pocket, outside the platform's fee. A fair "true cost to sell" comparison would need to add your own packing and shipping cost to the Etsy/Shopify/eBay columns before comparing them to Amazon's all-in number.
Shopify's number doesn't include the plan itself. The $1.90 above is only the per-order payment processing charge on the Basic plan — it doesn't include the $39/month subscription Shopify charges regardless of how many orders you get. Spread over 20 orders in a month, that's another ~$1.95 per order; spread over 200 orders, it's closer to $0.20. Shopify's real per-order cost depends entirely on your order volume in a way none of the other three platforms' fees do, since none of them charge a base subscription.
The ranking itself can flip with price and weight. Amazon's fulfillment fee is weight-tiered and eBay's per-order fee jumps once your order total passes $10 — so a $9 item and a $40 item of the same weight can rank these four platforms in a different order than the $55 example above. Run your own product's actual price and weight through the Marketplace Fee Comparison tool rather than assuming this example's ranking holds for a different sale.
What none of these fees measure
Fee stacks say nothing about traffic, buyer intent, return rates, or competition — an Amazon listing plugged into Prime shipping and built-in search traffic can out-earn a technically cheaper Shopify store with no visitors at all. Fees are one input to "where should I sell this," not the whole decision.