7970 (you wrote 7950 there!) Shouldn't be a tier higher but just like 5-10% faster. But What I like from the 7970 is the game bonus which includes titles such as Far Cry 3, SLEEPING DOGS, HITMAN Absolution, Bioshock Infinite, Crysis 3.
I apologize, I edited it.
Yeah, I think the difference ($30) is justified in the difference of performance + games bonus...