Samsung EcoGreen F2 HD103SI 1TB SATA Internal Hard Drive for $79.99 shipped.  Here is a screenshot, along with more information for your reference.  This is a 5400RPM drive designed to be energy-efficient instead of maximum speed, which makes it a more appropriate storage drive than a boot drive.  Note that it comes in OEM packaging, which means no pretty retail box but is otherwise identical.  Most places have it for over $100.