well, I'm using an x1950 pro, the price of these things are about £90 which is great considering they're 80% the speed of the top noch GF8800's. Although it's only Direct X 9, there ain't any Dx10 games out the now and no-one knows how current DX10 cards would perform in them yet anyway.
By that time, there will be another gen of DX10 cards out anyway.