Without knowing the price of the second 6800GS, I can't really say whether it would be worth it. If you can get the card for $40, then yes. If you can't buy one for less then $75, then probably not. I also wouldn't worry about getting a DX10 video card. The 8600GT and 2600pro/XT don't really have the power to use DX10. If your LCD runs at 1440x900, or 1280x1024, then neither of these video cards would be able to make it worth while.