I just bought this:
http://www.ebay.com/itm/171851993205
I offered $100 (before shipping), and they accepted. Probably could have offered lower (so it ends up being $100 shipped), but I can't believe how much the Asus P5A motherboards alone are going for.
The CPU being only 350 MHz will probably be helpful in letting me adjust down to play old DOS games without speed issues, and if I want, I could always plop in a Pentium 166 MMX. I don't think I need to, though. I may be able to get it down to 2.5x 66 (166 MHz) (I don't recall this CPU being multiplier locked). My goal is to have the ability to play old 386/486 games without speed issues.
Update: Seller just informed me it's a rev 1.04 board. I don't know if that's good or not. I read somewhere 1.06 has issues with K6-II+ and K6-III+ CPUs, but earlier boards do not. Other than that, i wonder what issues rev 1.06 addressed.