System Buyer's Guide under $825
Page 2 and Page 3 have some suggested parts for an AMD or Intel PC for under $550.
Although the prices are almost 2 weeks old (May 14th), perhaps the following might be worth considering:
Sony Optiarc Model 7240S-OB (optical drive)
Acer X193W+BD 19" Widescreen LCD (monitor)
Microsoft CA9-00001 PS/2 Keyboard and optical mouse [/url]