I would try to save for this roller:
http://www.carolinasrc.com/Webstore/...dproduct=11121
When you are ready the price may be down some on them. Depending on what you want I'll suggest a few good things to go with it that are not "high priced".
http://www.carolinasrc.com/Webstore/...dproduct=10021
http://www.carolinasrc.com/Webstore/...idproduct=4715
It sounds like you may have some stuff you need. What radio did you have? Maybe you can get by with just a reciever for your radio.
You also said you have some decent servos. Use one of those in the throttle and this in the Steering:
http://www.carolinasrc.com/Webstore/...idproduct=1690
Although there are many other good servos. Check into the ace 1015 as well.
You willl also need a starter box.
http://www.carolinasrc.com/Webstore/...idproduct=4474
No alighnment needed and works buggy and truggy. You will need two cheap 7.2 volt packs and you probably have a charger. It will be hard to be cheaper than $500 and do it right the first time. Save yourself some troubles and save up and do it correct.