Originally Posted by AmericanSensei
Next upgrade I do will be Nvidias DX11 lineup in GPU's, which is the 400 series???
Correct, but you might want to consider ATI's new cards. All we have as far as pricing are rumors, but it seems that nVIDIA will have to charge quite a bit for their cards because of the extreme yield issues they were/are having with these GPUs. That is the real reason the release date has been pushed back so much.
The best example of ATI vs. nVIDIA in the price/performance game is definitely the GTX 280/285. Sure it's an amazing card, but ATI beat it by significant amounts with the HD 4890 and 4850 x2, which were both priced cheaper.
If you want it for folding, keep in mind that the GPU3 client will add openCL support, which HD 5xxx cards have, so they should finally be able to perform well.