There's a futures market on Bitstar and it was trading at 0.04-0.05 BTC per coin yesterday. But it was on very low volume -- I don't think many people use this exchange -- so I wouldn't take it too seriously. Also, there is no publicly available code, and no confirmation of replay protection, so it is difficult to accurately assess the potential value at this point. Without those things confirmed, we can't expect exchange support, and if exchanges do not support it, it will be dead on arrival.

I think it's basically a scam, so if we can sell out BTG it will be to greater fools. Sell what you can early on. I wouldn't expect Bitcoin Gold to succeed for fundamental reasons, though it's possible it could pump someday due to hype.