Well your post was around in the middle of this conversation and not the 1st :P.
Actually, to suggest SLI, I was....
Also even if he sell his 660ti (lets say the new has a price of $280 at least, he could sell it for $200) he also needs an other $185 in order to reach the cheapest 7970 at the moment we speak at newegg. An other $185 for 21-32% performance (depends on nonGE to GE).
The OP has since made it clear that he intended to buy bioshock and Crysis.... If he gets $200 for his card.. That's $320, He can get the XFX dual fan card for $350. For $30... Yeah, I'd upgrade.
It is not worthy to do such a small upgrade for so much money.