Actually, some 7850s can go down as far as $160-180 each and can overclock better than 480s can, so if you really want two cards, two 7850s would be better. They also have much better scaling and two 7850s use less power than a single 480, so power is no big deal with them. For a single card, the 7950 is king when overclocking is considered and you want to keep costs down and with overclocking, can actually beat two 480s if you choose a good model, so not only would it have the advantage of being a single GPU setup, much lower power consumption, and better future-proofing with more modern feature support and twice as much memory capacity per GPU, but it could also be faster at about the same price. Not even water cooled 480s will beat some air-cooled 7950s.