I might interprete your thread title wrong but im going to assume you are asking this coming from a 9800 pro, in which case i would say you should probably NOT buy anything right now. the 6800np is a better card, certainly better than the 9800 xt but i wouldnt expect to get a fantastic value out of that card at all. if you really want to upgrade, i would save your money untill you can afford a gt, or wait to see what happens with the half generation. im sure something much more interesting will come out, as the current top models are surely to be replaced in much the same way the 9700 was with the 9800 within like... months of its release.
if your looking for high end performence, dont go in with a budget, save your money untill you can actully buy somthing worthwhile. thats my 2cents. if i had a 9800 pro right now, i would be pretty happy.