Walmart have been selling their Everex PC for a while now, and they’re currently priced quite reasonably at $130. It features a 1.5 GHz Via Technologies C7-D processor, 512 MB of DDR2 RAM and a 80 GB hard disk drive. The gOS (good opereating system!) operating system it comes with is a Debian derivative based on Ubuntu with a unique Enlightenment desktop window manager.
The GUI takes a little time to get used to.