Newtekie: that's the best way to do it! Did it with my 9800gx2.. Got the 280 for shipping costs!
With Evga, it's sometimes the better way to get a newer card just to set-up.. The reason for it, is that once a die-shrink, or a new series of cards come out, the pricing goes WAY down..
The 9800gx2 was a perfect example. Was $599 for the card, then you where seeing the week the GTX series came out, it went to $320 almost..