AliExpress

Price drift between listing and purchase, and your margin

You research a product, calculate a margin, and list it. Months later the supplier price has moved, your listing price has not, and the margin you believe in is fiction.

Why it goes unnoticed

Because the cost is only visible at the moment of purchase, and at that moment you are working through a list rather than evaluating economics. A price two percent higher than last month does not look like anything.

Accumulated across a catalogue and a few months, those invisible increments are the difference between the margin you plan around and the one that shows up.

Promotional prices are the main trap

A lot of AliExpress pricing is promotional. Research a product during a sale and the margin looks excellent. The promotion ends, the price reverts, and the product is marginal.

Check whether the price you are modelling is a promotional one before building a listing around it. If it is, model the regular price and treat the promotion as upside.

Shipping moves independently

Item price and shipping cost are separate and change separately. A stable item price with rising shipping is a common pattern and an easy one to miss, because the number you glance at is the item price.

Model landed cost - item plus shipping - and record that, not the item price alone.

Record what you actually paid

The defence against all of this is recording the real cost on every order, at purchase time. That gives you a history per product, and the history is where drift becomes visible.

Without it, the only signal is the aggregate monthly number, which tells you something is wrong without telling you which product.

A simple monitoring routine

• Compare the cost you paid this month against the cost three months ago, per product
• Flag anything that has moved more than a few percent
• Re-check landed cost, not just item price, on your top twenty sellers monthly
• Reprice or delist anything whose margin has fallen below your threshold

The currency layer

If you buy in one currency and sell in another, exchange rate movement changes your cost with no supplier price change at all. Over a year that can be larger than any drift in the listing price.

Recording the amount in your own currency at the time of purchase captures this automatically, which is another argument for recording actual paid cost rather than a modelled one.

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