How to tell whether an Amazon discount is real
Most of the work of finding a deal is deciding whether the discount in front of you is a discount at all. Here is what we check, in the order we check it.
Find out what the price actually was
A struck-through "list price" is the manufacturer’s suggested price, not the price the item has been selling at. Those two numbers can differ by half. The question worth asking is never "what is it down from" but "what has it cost for the last three months" — and that is a different number, available from any price-history tool or from the retailer’s own price-tracking chart.
Treat percentages as arithmetic, not as claims
A percentage is only meaningful if both numbers behind it are real. We show no percentage at all unless the current price and the original price both came off the listing, because an estimated discount is worse than none: it looks like evidence and is not.
Watch for the pre-sale markup
The oldest trick in retail is raising a price for a fortnight so the sale price looks like a cut. It is visible in any price history as a short spike immediately before the discount. If the "was" price only existed for two weeks and the item spent the previous six months cheaper, the sale is the normal price wearing a costume.
Check the size, count and variant
Discounts are often applied to one variant of a listing while the reviews and the photography belong to another. A 40% cut on the 12-pack means nothing if you are looking at the price of the 24-pack, and a colour or size can carry a completely different price on the same page.
Be suspicious of enormous numbers
Anything above about 85% off is more likely to be a data error than a bargain, and 100% off is always one. Genuine clearance tends to land between 40% and 70%: deep enough to move stock, not so deep the retailer is paying you to take it.
Decide before the timer does
Countdowns and "only 3 left" counters are conversion tools, and they work by moving you past the part where you decide whether you wanted the thing. The discount is only a saving if the purchase was going to happen anyway. Everything else is spending, at a discount.