Ask HN: Help with updating development hardware

I currently have a Pentium4 630 with 3 gigs of ram that I bought for 150 bucks a year ago that has acted as my main dev machine. I run Windows 7 64 as the host OS and a few different linux flavored VM's for development. I like having a separate VM setup for each development environment that I work in, ie dev1 for Java, Dev2 for Python, dev3 for PHP. This allows me to change the OS environmental variables and permissions without changing things for other projects. The biggest drag on this setup is that I quickly run out of RAM between W7, 1 Linux VM, and Eclipse causing me to suspend one VM to open another.

Question: I would like to build a machine that can handle multiple open VM's each with an open eclipse instance as well as db, and java vm's running on each instance.

Paravirtualization would be nice but that seems like a pipe dream at this point, at least from a client perspective, I want to interact with the desktop as normal so Type 2 (VMWare) seems to continue to be the answer.

here is a list of my initial criteria: RAM: 8-12 gigs CPU: ?? MOTHERBOARD: ?? PRICE: <500$

An overstock server seems like a possible option although the server spec components tend to be more pain than its worth for desktop use. I'm not looking to run the latest and greatest hardware, just something that wont get memory bound and can handle 3-4 VM's running computations at once without dogging. Not too much to ask right? ^_^