FYI, P31/G31 is hard-limited to 4GB MAX and does not support memory remapping, so you'll run into the 'old' 32-bit addressing limit when populating 4GB RAM, even with 64-bit OS. May or may not be important to you.
Originally posted by: MagickMan
The $70 limit is a bit limiting, unless he can stand for a micro ATX board. I guess he could go open box, I suppose.