If you're going to get into racing. Go down to your local track and talk to some of the racers. They usually will tell you what they are running, what to get to start off with, and other cost saving things that someone starting up would not neccessarily think of. That is one of the things I like most about racing is the guys are almost always willing to help if asked (and sometimes not asked).
And at times some of them will have decent equipment they would be willing to sell you (usually because they have upgraded to even better equipment).
Look at ebay (be careful though). You can generally get some good deals on some of the cars you are looking at. If you go this route, look for one that someone has obviously cared for. This is how I got my Delta XP4 in good condition.
My suggestion to start off with:
Car: Mugen Mtx3/4 (the mtx4 just came out, but the 3 will be just as competitive for awhile), Kyosho RRR, Serpent 710, RD Logics Mongoose (you can get this for about $200), NTC3
Engine: OS TZ seems to have the best bang for the buck, though I still prefer Novarossi (novarossi based) motors. (I wouldn't buy used unless you know the person selling it to you)
Radio: JR XS3, Airtronics MX3-s/MX-8 (you don't need a top top end radio but something with some adjustability and FM modulation)
Servos: Digital steering, analog throttle (I am using a Futaba 9451 for steering, and Futaba 3010 for throttle) [again don't go too crazy, two decent analogs would work as well]