Half the mat listings we mapped had no price at all

Our first price run returned four live prices out of thirteen listings. The other nine came back verified but empty: the right product, no price.

The cause turned out to be uninteresting and important. Most of the codes we had collected were variation parents — the entry that groups every colour and size of a product together. A parent has a title, images, reviews and a browse category. What it does not reliably have is an offer, because you cannot buy "the mat in any colour". Amazon returned availability of OUT_OF_STOCK with no price attached, which is technically accurate and practically useless.

The fix

We searched the catalogue for the specific child listings — a named colour, a stated length — and verified each candidate title against the model before adopting it. Live prices went from four to ten out of thirteen on the next run.

The three that remain without a price are honest gaps. One mat is currently unavailable on Amazon altogether. One is a brand that does not sell there. One is a listing we have not been able to verify to our own standard, and until we can, the page says the price is missing rather than guessing.

Why write this down

Because it explains a pattern you will notice on comparison sites generally: prices that never change, prices that do not match what you see when you click, and prices with no date on them at all. A parent listing will happily give you a "from" figure that belongs to the cheapest variant in the group, which may be a different size than the one being reviewed.

Our rule is narrow and easy to check: the price shown is the price of the specific variant named on the page, read on the date printed beside it, or there is no price shown.