You can get a Galaxy GeForce GTX 580 from NewEgg at this very moment for the measly sum of $390, $360 after the MIR and get it shipped to you for free! If you prefer an overclocked card the the EVGA SuperClocked GTX580 will run you a bit more at $440, with a variety of other models available between those two benchmarks.
That reduction of over $100 makes the price to performance ratio change significantly as now AMD’s HD 7970 costs $150 more than the GTX 580; however the performance difference between the two cards is only about 10%. While a difference of $50 did represent about a 10% price difference, after these cuts that is no longer true. NVIDIA has changed the high end graphics card market already, without having released the GTX 680 yet. Once that hits the market in the not too distant future, AMD is going to have to rethink their pricing in order to stay competitive. The mid-ranged HD 7870 is within $40 of the current price of the GTX 580 which makes those two cards direct competitors, which was probably not AMD’s intention, though the performance numbers are close enough to make it a contest.