Oh yeah, I'm reusing the 2 optical drives, and the GPU... maybe.
My budget is about 300 USD. I can go a little higher. Tiger Direct has some barebones kits, bundled parts, if you will, that have more RAM, the motherboard and faster chip, an HDD, a bigger GPU and a better case (mine has damaged front USB ports and now nonfunctional headphone and mike jacks) for less than $250.00. I have an OS waiting for me. Oh and it comes with a fan for the CPU and a nice big power supply... which means I'll have a spare FOR ANYONE WHO MIGHT NEED ONE COUGH COUGH.
The kit I have my eye on is an upgrade in terms of HDD space, RAM, CPU speed and GPU. I'll link it in the morning; I'm at work and the web filter won't let me on TD for some reason.
I've ordered from them before and I was satisfied with their stuff.