You'll have to do the research for pricing on the chassis. There are a few different models. I think the latest and greatest is the TA05 v2 VDF or something like that.
Belt driven is a good idea as it's easier to get overdrive/underdrive happening, and you don't get torque steer from the mass of the rotating shaft.
Otherwise, you'll need esc and motor ($100 like I said), a good servo (look at the savox 1257 $69) and radio gear. Radio has alot of options, but I'd say something like spectrum dx3c ($129) is about the ballpark for a good radio. If you don't want multi model memory and exponential and such then flysky/hobbyking/eurgle make one for about $15. Both are 2.4ghz.
Remember to leave say about $100 in your budget for crap you don't think about normally. Things like motor pinions, wheels, tyres, body, paints etc.