A few years ago I had a new PC done by a local computer shop. For less than $500 I got a 1.2GHz AMD Athlon processor/motherboard, 40mB hard drive, 256k memory, CD writer, 350 watt power supply and a decent graphics card in a nice case. They also took care of a few issues that popped up afterward on a morning to afternoon basis. That's why I like dealing locally rather than Dell or Best Buy, etc.

You should check your local shops and go to CNet for reviews and commentary on components to know what you want.