[Freak_NL]

The market price for two used hypothetical coffee makers¹ (same manufacturer/type/age) is rarely the same. One has scratches, stood in direct sunlight for years, and has a few parts in need of replacing soon, the other was used twice and has sat in a cupboard ever since. Both work.

Besides, who keeps receipts for anything but expensive items that might need warrantee? Most people don't. Sometimes you acquire something through different means: presents, inheriting, thrift shop, etc.

And that's avoiding the huge privacy matter of buying something with a unique tracking number attached and linked to you.

1: I'll take mine without hypothetical sugar please.

[EricRiese]

Who keeps receipts? That's the point, you would if it was easy. It's automatic like keeping a email. I have all my credit card transactions going back years. It would be the same.

It wouldn't be linked to me as I envision it.