Blair Tech Group via eBay offers the refurbished Dell Optiplex 740 Core 2 Duo 2.1GHz Desktop PC for $139.99 with free shipping. That's $10 under the lowest total price we could find for a refurb with half the RAM and hard drive space. It features an Intel Core 2 Duo 2.1GHz dual-core processor, 4GB RAM, 160GB hard drive, Gigabit Ethernet, DVD burner, and Windows 7 Professional.

A 1-year warranty applies, although it's unclear who backs it.