What we learned the expensive way.
Working notes on Amazon-to-eBay arbitrage — policy, pricing and the arithmetic behind a real margin. No growth-hack listicles.
eBay Fee Calculator: How eBay Fees Actually Work
A flat 13% is the wrong number. The fee is set by category, charged on the total including the shipping you collected, with a fixed per-order charge underneath. The full arithmetic, worked through.
Read the pieceeBay Automation: What You Can and Cannot Automate
eBay publishes an API precisely so sellers can automate. The line its policy draws is elsewhere — and which side a tool stops on is the difference between leverage and a suspended account.
Read the pieceeBay Arbitrage Software: How to Choose One
Every vendor’s feature list is the same list. Four questions — where sync runs, how fees are computed, what happens at zero stock, and where automation stops — separate the tools that pay for themselves.
Read the pieceAmazon to eBay Arbitrage: The Complete 2026 Guide
What the model actually is, which eBay policies decide whether you keep your account, and the arithmetic that separates a real margin from a felt one.
Read the pieceHow eBay Order Sync Actually Works
Why some tools stop syncing the moment you close your laptop, what an official API connection does differently, and how to tell which one you are using.
Read the pieceNever End an eBay Listing When Your Supplier Sells Out
Ending a listing throws away its search history. Setting quantity to zero keeps it. The difference is worth months of ranking.
Read the pieceYour Supplier Raised the Price. Now What?
Three options, one of which quietly loses money on every sale. How to decide in seconds instead of finding out at payout.
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