Retail arbitrage

How the margin actually works

Every arbitrage deal is the same four numbers: what you paid, what it sells for, what the platform takes, and how long your money is tied up. Beginners track the first two and get surprised by the third. Experienced sellers treat the fourth as the real constraint, because capital stuck in slow inventory is capital that can't buy the next markdown.

A worked example. A tool marked down from $199 to $49 looks like a 75 percent discount and a $150 spread. Sell it on Amazon at $130 and the referral fee takes about $19.50, fulfillment on a bulky item takes $12 or more, and inbound shipping takes another $6. You are at roughly $92 net against a $49 cost — about $43, or 88 percent return on the money you spent. That is a good deal. Run the same math on a $12 item marked to $4 and the fees eat most of it.

This is why depth of markdown matters more than percentage off. A 90 percent discount on a cheap item is often unsellable after fees; a 60 percent discount on something that carries a high enough price to absorb the fees usually is not. The profit math guide works through the full fee stack, and the sales rank guide covers the other half of the question: whether anyone is actually buying it.

What the scan data says

A lot of arbitrage advice is folklore passed between videos. Some of it is testable, and when we test it against our own scan history it does not always survive. Two examples that show up in these guides:

• The Home Depot "cents code" system is not real. The widely repeated claim is that a price ending in .06 or .03 signals a specific markdown stage. Across millions of price observations, those endings account for a fraction of a percent of clearance prices and do not predict what happens next. What does predict a deeper cut is the thing you would expect — a price that has already dropped once, paired with falling on-hand quantity.
• "Markdown day" is a regional habit, not a corporate schedule. Retailers do cluster markdowns, but the day varies by market and by department, and it moves. Treating a specific weekday as gospel is how people burn gas. The markdown schedule guide covers what is actually consistent versus what is store-level noise.

Where to start

If you have never done this: read the legality guide and the startup cost guide first, then the profit math. Those three settle whether this is a fit before you spend anything. If you are already sourcing and want to be more efficient, skip to markdown schedules and route planning.