Newegg offers the refurbished Lenovo ThinkCentre M58 Intel Core 2 Duo 2.5GHz Desktop PC (no monitor), for $129 with free shipping. That's $170 off list and the best price we've ever seen for any ThinkCentre M58. (It's also $71 under the lowest price we could find for a refurb of a similar model.) It features an Intel Core 2 Duo Quad-Core 2.5GHz processor, 4GB RAM, 160GB hard drive, DVD drive, and Windows 7 Pro 64-bit. Deal ends March 30.
A 90-day warranty applies, but it's unclear who backs it.