you should SLI that baby and OVERCLOCK it to the max! it will beats 4580 CF
WTF are you smoking? if he had the 512MB version, I would bite, but with the old g80 card, theres no way it can touch 4850 CF.
I agree with others here, in your current situation, I would grab an 8800GT/8800GTS-512 or a 4850 and enjoy.