I have an X850XT and the fan is starting to go bad. But I do have a compusa replacement plan on it. Should I stick with the replacement card they give me or pay the difference and grab a better card? The X1900gt ($350 value) looks to be the closest card that they sell in-store. I noticed they only sell the 7900gt online. Should I pay the difference from the X1900gt and get an X1900XTX (I'd pay $250)?