I built my computer for about $250 after rebates.

I found everything on Techbargains.com just use the "search" function to find what you want.

I have...

1 Gig Memory
AMD Athlon 64 3800+ CPU
NVidia 6150 on-board video
2 40 GB hard drives
Windows XP

I can play with the medium-high settings on Sim X under this confiduration.