You could upgrade the graphics card. It can be from $90-120.00. RAM is also a priority, 1 GB is recommended if you ask me.
A client of mine does 3D rendering freelance work from home. He does not do any animation, but makes minimally-textured 3D models of projects that construction companies and other firms will build. The only problem is that his home computer, as opposed to his work computer, does not have the performance he is looking for.
The computer currently has a 1.8ghz Pentium 4 processor, 512MB of Ram, and a 64MB Video card (I don't know which brand or kind). What I am wondering is what PC components (memory, video card, processor, etc.) should I upgrade for him to get the best performance. I would like to stay away from processor upgrades as they will be too costly for his low budget, but if that is what affects performance the most then I will let him know that. Any help in this aspect will be greatly appreciated.