|It would be best to just keep your current system as-is & use as a 2ndary system.|
Here's what you'll need to build from scratch:
- power supply
- video card
- hard drive
- DVD burner
- operating system
If you watch the sales & don't mind dealing with rebates, you should be able to build a decent gaming system for under $600. If you're in the US, check sites such as Newegg, TigerDirect, & SuperBiiz.