After exhaustive testing, I believe (with the help of this great forum, I never would have found it otherwise) that the source of my father-in-law's PC problems (inconsistent freezes and various other quirks) is a bad mobo, due to blown capacitors.

Ok, I don't have an issue with repalcing the mobo, done it many many times.

What I'm having troubles with is locating a good one for a reasonable price.

Can anyone suggest some brands (and even better) particular models?
I've been trying to locate an ASUS or Gigabyte, (looking on ePay and Craigslist). (he's on a fixed-income, so I was going to buy it for him, but wanted to keep it under $50 if possible).

I'm looking for:
socket 478 (Pentium 4, 3.06 800fsb)
DDR memory
AGP 8x
IDE support (HDD & DVD burner)

Suggestions / links / recommendations would be greatly appreciated.

Thanks Guys!