I don't, but there is ONE exception.
I have a collector ''friend'' IRL who's a total swindler and reseller. He doesn't even game much at all, his collection is a huge trophy piece. Whenever he finds doubles of games (which he often does, he's in yard sales every effing weekends) he either sells them to us, his collector ''friends'', at eBay prices even though he gets them at a buck or two, OR he doesn't even want to sell them to us because some random game shop will give him pretty store credit for them. Plus he doesn't bring his gamer ''friends'' game hunting because he doesn't want deals to slip away from him (he always brings the same guy that doesn't collect).
He's a major league a-hole and when HE finds good deals I just want to kick him in the nuts.
End of rant.