8800 GTS max oc g92 sli vs 9800 GTX+sli on q6600 3.4ghz

how big of a difference will a 9800gtx+ sli be compared to a 8800gts g92 sli oc to the max be on a q6600 3.4ghz. I made another build but got a 8800gts g92 for only 120 bucks brand new evga price after rebate. so that was a good deal i couldnt pass but when i went to find another 8800gts its like $180 bucks and thats a S$&# load that i dont want to spend, i was thinking i should have just went with a 9800gtx but the 8800 gts was such a great deal. but anyways how much of a difference would those two be if they were maxed out overclocked. and the heat or power consumption differ. I cant find anywhere that ive search to see a price that i want for an old 8800gts g92 at a reasonable price for me i would like brand new 150 bucks but everywhere is soo expensive can somebody tell me where i can find really cheap 8800 gts, I play at 1680x1050 22in, wants to play crysis max