How to tell if a "was" price is inflated
The crossed-out price is set by the seller. The discount that matters is against what the product actually cost over the last few weeks, not against the highest number it ever had.
Reviewed
An example from this week
On November 5, 2026, a Lenovo V14 G5 laptop (Core i7, 16 GB, 1 TB) was 629 USD at Walmart. barato.si had seen it on 28 days before that: the lowest price was 629 USD, the highest 859.99 USD and the median 629 USD.
A "was 859.99" would be a real price from some day, and still a bad yardstick: it nearly always cost 629. That is why barato.si did not flag it as a discount that day. Buying at 629 is fine. There just isn't a 27% discount.
What to check before you pay
Look up the history. A price-history tool shows what it cost day by day; if the product is on barato.si, its row shows which reference it is compared against and where that comes from. If the "sale" price is what it cost most of the month, it isn't a sale.
Be wary of list price. In electronics and home goods, the manufacturer's list price is often a number almost nobody pays. barato.si labels those references "unverified".
Check whether the reference went up just before. A product that goes from 40 to 60 in October and back to 40 in November "at 33% off" did not get cheaper.
Compare another store. If the same model costs the same elsewhere with no sale banner, that is its price.
What the US rule says
The FTC's guide on deceptive pricing says a former price is a fair comparison only if the product was really offered to the public at that price, regularly, for a reasonably substantial period. It is guidance, not a promise every store follows it, so it pays to check yourself.