It's a crap shoot... I wouldn't do it again. I got a 9700 pro that possibly a kobra type had ran way out of spec, damaged the core/memory, and then smugly returned it. It was obvious it had come out of someone's system by it's looks. It came with no power connector and no drivers (no big deal). It worked fine at stock speeds for awhile and then, right about the fifteenth day, it started to artifact after heavy use. It then started artifacting even more to the point that it became useless and it was too late to return.
As much as I read here about people having no qualms returning merchandise that they screwed up trying to get that extra 500 points of 3dmark bragging rights, I just don't see it worth the hassle.