Recent pet peeve:
Parts being sold as NOS when they are actually a used parts in nice condition.
An NOS part boxed in its original Mopar box is sold, used by the new owner on a restoration, who puts the prior, broken, but near mint part into the box, and sells it at a swap meet.
It changes hands once or twice, each time the seller purporting its NOS with shelf wear. We buy the part, maybe pay a bunch for this alleged NOS part, only to find out its busted! It may look pretty, but still... it's busted!
Not happy, Bob. Not happy.