That's as low as it goes my friend.
I have two dual boards, an Abit VP6 and and ECS D6VAA. The VP6 has 1 P3 @ 1125 in it and I'm getting a second 1GHz for it next month at a computer show. The D6VAA has a single P3 700 in it and I'm going to stick two new 1GHz P3s in it so I'm looking at buying 3 of those things.
I had planned on building another AMD system but decided against it to put the upgraded CPUs in the ECS system. I just don't have the room for ANOTHER PC at the moment as much as I'd like to build one.
The computer show is the last weekend of next month, so I'm hoping to see them drop a little by that time. At least in the $150 range. Still a big chunk of change when getting 3 at once.
Dual P3 s rock though. I did have the VP6 running with two for a while (don't ask what happened, long story) and loved it. Superfast. I've got an old P2 350 dually plugging away at SETI too.
It won't be cheap but if you decide to go for it, mark my words, you won't regret it at all. A VP6 or D6VAA (not quite as good for overclocking and no RAID, unless specified, but an excellent CHEAP [$69 shipped!] dually mobo) 2 P3 1GHz @ 1125 (or 1200+ which they can do but my RAID controller craps out) and 512MB of Crucial PC133 at CAS2 on a 150+MHz FSB will flat out chug.
If you go with the ECS board you could get by with around $420 after S&H. Tag another $50 for a VP6...maybe a few less.
Let us know what you decide.