Basic Radio Kit to fit a secondhand "roller"?

[Shorty]

Hi,

Wanting to get into racing and buy something competitive, but cheap.

Been looking at buying new RTR B4.1 or similar but someone suggested by a used car from ebay or from the oople forum sellers.

All the used cars seem to come without electrics, most even without motor!

So how would I budget for my electrics? What would be a good radio, servo and ESC set to get me going, to drop into a secondhand car?

Needs to be capable to race, but not the best kit.

I don't know what features of a radio a really required. Why do I need 3 channels when 2 will drive the car? Steering response based on speed sounds great, but in reality is it needed?