The cheapest 560ti on newegg right now is 210 after MRI, and its EVGA they are pretty good about MRIs. IMHO for $40 dollars more a 560ti-448/570 is a much better upgrade than a 480 or a 560ti. But if money is no problem, 580s are good buys, now 1.5 or 3gb? Decisions decisions....
But wait for Kepler, supposed to be 500, AMD and Nvidia will have price wars and the cost of everything will drop even more, I think its supposed to be out this week, next monday. Non of the release dates are official, but it is extremely 99% likely to happen in the next few days.