Listen: let's talk about an auction for an unreleased proto on a CD. The seller says that it is unique, only one opportunity to get the game. The auction looks completely legit.
I bid but someone overbid me. I am the second in the bidding history: ok, I didn't want to spend more than that, also if that was unreleased.
The day after the seller contacts me and says:

Hi I noticed you bid on my ******, I have a duplicate copy here, again on a CDR I can give you a second chance offer on a duplicate if you wish at *** via ebays second chance offer - I'm only saying this as you wont get another opportunity to buy this game. let me know either way if you want me to offer this. cheers
How many copies will he do?
I really don't like this way of selling protos: the winner of the auction looks cheated to me.