Have a xfx 6770, and wondering if getting another one for $105 after rebate and a game, is better than upgrading to a 6870/6950/7850. I know overall that those 3 are better than one and prob two, cause i heard that a cfx 6770 was similar to 6950. a 7850 is kind of out of my price range and would prob lean more towards a 6870, and only a 6950 if i can get the rebate lol.

I play multiplayer battlefield 3 @1080p and get decent fps with just one atm, how much better would the crossfire setup be for the lower cost of another card?
 
Solution
Crossifre would give you between 6870 and 6950 performance. The 7850 would be better than all of them.

Crossfire does have its issues, but if money is an issue then definitely go for crossfire.