Normally i'd say $550 is insane, but this card does seem to be as fast as 2 6800's, which makes it not bad relative to other high end vid cards, and the fact that its got 300 million transistors just amazes me. The part is probably actually worth it in more ways then you ussually see. Plus you can add a 2nd in sli for whenever doom 7 or half 5 comes out.
Hope this isn't too much opinion for the hot deal forums, but the 300m transistors amazes me enough to say this is worth it if your into top of the line graphics. Still way outta my price range anyhow