Think the cheapest 7950 in my country is ~350$, about 50$ more and a 7970 could be gotten, so its not a good price/performance (about mid range). Made a chart so the stuff can be seen the easy way.
Raw price (low to high) (taking into account it can be hard to make such a spec "ultimate" because vendors got big influence, so i tried to find the best prices i can find):
Note: This is my countrys best price, not Newegg. Newegg for example is 300 $ for 7950, making it a very good budget card in theory (still weaker than 760), however, most of the other cards are more or less in the correct chart order.
660 TI (no OC): <230 $
760: <260 $
7870: <270 $
660TI (factory OC): <270 $
7950: <350 $
670: <370 $ (price recently dropped a lot but still way to less, because other cards dropped even more. Probably because 670 GTX is very popular so the price is "pushed")
7970 (GHz): <400 $
680: <430 $
770 <450 $
Raw Performance (low to high) (taking into account that all may have around same OC potential, using newest drivers of course):
660 Ti = 7870 (comparable)
760
+15%
670 = 7950 (comparable)
+10%
680
+10%
7970 (GHz)
+5%
770
+5%
Of course in term a "weaker" card is a good OCer, nowadays its no problem to reach the performance of the next higher card, because the performance steps are to minor and most of them OCs pretty well. So, luck of the draw can achieve "comparable" performance for lesser price but thats a lottery and not a "given performance". The flagships are no true flagships anymore, so the decision for getting cutting edge may be hard and price/performance is currently a high focus for most people.
Finally the price/performance chart:
1. 760
2. 660 Ti
3. 7870
4. 7950
5. 7970 (GHz) = 670 (comparable)
6. 770
7. 680 (sad to see but apparently true)
Note: In term the 7970 is same
price/performance such as a 670 GTX but stronger at
raw performance, then the 7970 is at advantage. People mainly chose a 670 GTX because
apparently lesser "microstudder", a matter im trying to investigate (true or not, problematic or not). Considering the "Skyrim issue" im unable to find a solid proof that the Radeon could be inferior. The
frame time variance would be able to show the microstudder value and
the 7970 was very good at that spec. It could probably become a issue when Crossfired but for single GPU users there should not be a difference (making the 7970 the better choice).
As the final note: Nvidia in the past was almost
never good at price/performance, it was usualy a consumer market AMD is maintaining. Nowadays, Nvidia is in overall at least head to head with AMD considering that spec, which is kinda a surprise and a good proof that Nvidia is now trying to attack AMD way harder than they ever did. So we somewhat have a harsh battle. Nvidia is still trying to continue with theyr "old mentality" but just for the "super high end series", GTX 780 + Titan.