I’m in the market for a server replacement for the machine that runs this blog and a number of other domains. It needs to be as cheap as possible

What I’ve got now:

Pentium Celeron 1.7Ghz
one 80 GB drive
one 200 GB drive
1.5GB RAM

The drives are set up with an 80GB software RAID1 and a 120 GB extra partition that I use to hold my copy of the Debian archive.

Does anyone know where a decent machine could be found for this role? It does not need any kind of fancy graphics, but it does need to be very reliable, and not suck a ton of power. Dual core CPU and SATA2 would be nice, but not required. RAID redundancy is critical, but I do not need fancy hardware for this, just two drives.

Naturally I want to spend as little as possible, so used is better than new. Hardware donations are most definitely acceptable, if anyone is feeling so generous.