Tom ,
You outbid me on one of the chips, so I feel This is what you should do, I would Leave Negative feedback ,since the seller has a 100% possitive feedback.

If you know if the seller is a club member, Then put in a claim with the claim director.

If what he says is true about listing for a friend , He should still make good on the sale , and find some new Friends.
Just my Thoughts on this matter.
Marc Shapiro