ok sorry I was just doing my good samaritan :P. IMO I would prepare my computer for an overclock in order to get more power. I would do the following thing..
-New psu something like corsair TX650 89.99 (newegg)
-New high performance DDR2, G.Skill DDR2 2x2GB 5-5-5-15 90.99$ (newegg)
-New heatsink, artic cooling freezer 7 pro 36.98 (newegg)
-And finally sapphire 4890 vapor-x 1gb 209.99 (newegg)
426$ before taxes :P
All those part are available on newegg, us dollar and free shipping
And finally do a good overclocking of the cpu and gpu and you will have an excellenmt bang for the bucks