I build PCs, and $450 will get just the videocard and the CPU.
That doesn't include the required case, RAM, motherboard, OS, power supply, or hard drive(s).
With all that, to get a decent machine to play games well now and play ok into the future 3 years, you're looking at least $1000, not including monitor.
If you're playing on a big 24" LCD monitor and you want the full 1920x1200 resolution, then you're looking at least $1400.
At least, that's what I priced myself last week off Newegg while dreaming of buying it
