Too many of these to read but here is what I would do. If I didn't want to pay the $65 in the first place then I wouldn't do that. I would make him an offer of what I would be willing to pay (where I would have quit the bidding) maybe something like $50. I would make the extra $40 contingent on my receiving the item, that means he has to trust you. I believe in doing the right thing overall and not just taking advantage of others mistakes. Obviously he didn't want to sell it at $10 when he knows it's worth a lot more.