What most people don't understand is that it's the processor that's working when you render graphics(as in Photoshop, 3DSM), not the graphics card. So, I suggest the following if you want a computer for graphics editing:
Western Digital 80GB 7200RPM SATA Hard Drive, Model WD800JD - $65
Kingston 184 Pin 512MB DDR PC-2700 - $76
FOXCONN "K8S760MG-6LRS" SiS 760 Chipset Motherboard For AMD Athlon 64 Socket 754 CPU - $68
AMD Athlon 64 2800+, 512KB L2 Cache, 64-bit Processor - $127 (socket-754)
APOLLO GeForce4 MX440 Video Card, 64MB DDR, TV-Out, PCI, Model MX440 64MB-PCI - $49
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Total: $366 = approx $422CAN (at Newegg.com)
Should be enough for your needs. SATA and 64-bit processor is a big leap in performance.