I normally go with amazons used price and knock $10 off it.
I think their about $90 used on amazon so $70 shipped is a nice price. The thing can play most if not all games. I even played Crysis on it for awhile.
The 4870 will rock out on Crysis. I had the 4850, with a tri core and 4GB RAM, and I damn near maxed it out, my monitor was holding me back on the resolution, so the 4870 will *easily* play any game out there, provided the CPU is good enough.
My brother is playing the BC2 campaign, with the 4870. Wow, amazing. He only has a dual core, but the game looks so beautiful.
Anyway, $70 is a great price for the card. Too bad I have a laptop.