There are some amazing machines out there for as little as $300+. Crazy. You can get a nice machine PLUS a flat panel monitor from Dell right now for $519.
I'm probably going to get one to upgrade my one that is 5 years old.
You younger guys are lucky these days. I bought a Pentium 120 in 1995 with a 1 Gb hard drive and a monitor that weighed a ton for $2200.