I've had plenty of people flip games on me right after I sold it to them. In general, it doesn't bother me. I sold the game at the price I wanted, and they can do whatever they want with it. That being said, it really pisses me off when someone lies to me and buys the game under false pretenses. I've had people tell me that this is their grail and that they've been looking for one for years, and then they turn right around a flip it. That is totally uncool in my book.