Don't forget to check out one of your local friendly FIRST suppliers, intelitek Inc. (you know, the people who made EasyC)
I'll admit right upfront I'm a former employee (hence the plug) but the Super ProLight 1000 is a sweet machine. It's right in your budget and the best part is they also sell curriculum to support it and it's made for educational use so it's very user friendly and easy to learn.
No worries about crashes and expensive repairs, it's pretty bullit-proof.
Team 40's made tons of robot parts from gearbox sides to give-aways, you name it.
www.intelitek.com or swing by Team 40 at Championships and talk to any of the mentors.
-Sarah (shameless plug over now)