selling play money chips

I've heard of people selling play money chips for real money at poker sites. Has anyone ever done this before or know someone who does at pokerstars?

I've seen several threads on this subject. It may help to search the forums for those threads.

I haven't personally had any experience with selling play chips on PS. But, as I understand it you should have at least 1 mil+ before you consider selling them. I know there are several sites that I've seen that buy them, but I'm not sure they're legit...