I appreciate your concern for potential buyers. I'm aware of Zynga's rules about buying chips from 3rd parties but I've been selling chips for about 2 years now. I've sold roughly ~5billion chips for about £2500 and have never had a problem. Ever. The trick is to not make it obvious, some people make the amateur mistake of making a huge bet and then standing up from the table to lose the chips intentionally. This behaviour is a huge flag to Zynga.
I rarely play nowadays so I just want rid of these chips. I'm selling Steam games in my other thread so I'm not here to rip anyone off.