The 7950 is more than 250$, it's better than the 660 gtx non ti, it's about the same performance as the 660 ti, if you can afford a 7950, why not the 660 ti ?
Since you had a previous nvidia card, you might want the 660 ti.
But if you want the 7950, by all means, it has two free games, if it's why you're looking it for, the two games being crysis 3 and bioshock infinite.