The X800 Pro has went down in history as the worst card for the money of all time. $150 is a much more reasonable price for that card than it used to be, but $150 is still too much. Go for the 6800GS which wipes the floor with the X800 Pro.
P.S. I used to have the X800 Pro, I paid $400 for it when it came out, worst $400 I ever spent.