Seagate Barracuda 7200.12 750GB 7200RPM 32MB Cache Internal Hard Drive for $39.99 after this $20 rebate. Shipping $4.22, so the total comes to $44.21 shipped. Here is a screenshot before the $20 rebate for your reference. Note that it comes in OEM packaging, which means no pretty retail box but is otherwise identical. Most places have it for about $69.