I remember this being an issue bitd on eBay (late 1990's, Early 2000's), and then eBay came up with the rule that crazydean mentioned.
I think a corvette sold for like $50 or something. I don't remember the details but it was something that level of extreme.
Personally, I'd be disappointed but guess what just happened to me yesterday:
I bought Rayxanber 3 Sealed on Amazon for $135 last week from a seller in Japan. The order was immediately cancelled, and they informed me that they didn't have the game anymore. I wont mention how much the game is selling for sealed. I wasn't able to give them any feedback, either. The order was removed yesterday at noon from my history.
Was I pissed? Disappointed. And to be fair, I haven't seen that seller relist it (...but I AM WATCHING)
Similar shenanigans, Amazon style.