I guess you can buy just about anything anywhere. I mean, I could go to Kazakhstan tomorrow and I'm pretty sure there will be a nice market for 6600gt's. I bet they cost a helluva lot less there than they do here now too.
As I'm currently selling three different 4-series cards, I do of course realise that they can still be bought. However, I'm not exactly an official seller, and that is what I assume the OP is looking for, seeing as he didn't specify otherwise, the reasonable assumption would be that he was waiting on ATI lowering prices. This is something that they have absolutely no reason to do because they have no competition at any price point, and the 4x series are already extremely cheap considering what they were at release.