There is a seller on eBay selling a $6 card for $300. They have another $3 card going for a similar sum.

The charitable explanation is they don't know much about cards (their other items for sale aren't collectibles). Why they wouldn't do some research before posting is a head scratcher.

The less charitable version is they are hoping someone knows less about cards and buys them without doing any research.

Assuming it's the former situation, should I send them a PM and let them know their pricing is way off? Or just leave it alone?