You pay for the high FPS. Not a good value but a good performing video card.
That's sort of the way it works, though... Higher performing cards tend to be far pricier.
The 7950/GTX580/7970 don't compete against the low-end or mid range cards but rather against themselves in the upper tier. As was noted already, those perf-per-dollar charts don't say anything by themselves. Unless benchmarked at various games/resolutions and then tiered, they're absolutely useless.
As far as pricing goes, it's been uttered but it needs repeating:
Blame Nvidia, not AMD. Until the GTX580 is lower in price AMD won't and shouldn't budge. The card that performs worse should be the card that's cheaper and currently Nvidia is being stubborn. AMD hasn't ever made real money on their graphics cards, finishing some years in the red. Now with good market share, great reputation for performance and low power consumption they're looking to make $$. Justifiably so, they have the better cards.