I've got all the parts for a computer but a case, power supply, and sufficiently large hard disk.

I'm looking for:
1. mid size tower (I really don't care about the aesthetics, but it has to be transportable, and my motherboard requires at least mid size)
2. power supply of at least 450 watts
3. hard drive that's at least 200 GB

I'm looking to spend a total of less than $100. (newegg: case $50, hard drive $50, power supply $30)

I might be able to help you look, but what sort of hard drive? I'll assume Sata 3.0, but correct me if otherwise.

EDIT:
Well anyway, here's a few things to look into that I found in a few minutes of searching.
Hard drive:
HITACHI Deskstar 7K1000.B 0A38018 320GB SATA II 7200 RPM 16MB Buffer Hard Drive $40 after MIR

PSU:
OCZ ModXStream Pro 500W Modular Power Supply $29 After $25 Rebate
Newegg
OCZ ModXStream Pro 500W Modular Power Supply
$29 w/ Code OZSAVEOCT and After $25 Rebate w/ Free Shipping

Case:
Cheap cases can be as low at $15 at newegg, but for a slightly better one, look at these.
AZZA Orion $30
Roswell $35

I have a 480W PS laying around. Works perfect.
http://www.newegg.com/Product/Product.a ... Tpk=bks480
Make an offer if interested.