$140 for a hdd, case, and a good psu.

PCPartPicker part list: http://pcpartpicker.com/p/PUny
Price breakdown by merchant: http://pcpartpicker.com/p/PUny/by_merchant/
Benchmarks: http://pcpartpicker.com/p/PUny/benchmarks/

Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($59.23 @ OutletPC)
Case: Corsair 300R ATX Mid Tower Case ($59.99 @ Micro Center)
Power Supply: Corsair CX 600W 80+ Bronze Certified Semi-Modular ATX Power Supply ($44.99 @ Newegg)
Total: $164.21
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2014-05-24 09:17 EDT-0400)