I started off with the B4RS and the only upgrades I bought straight away were the aluminum front arm brace and a set of cvd's. The real expensive part comes when you decide to upgrade the electrics. Within a couple of weeks racing the RS i had bought a new ESC and motor and sold off the bits that came with the car. If you have a controller, receiver and servo, I would do as Mike suggested and buy the Team version (£120 from DMS) and see if you can get a second hand brushless set up from the sales section here. In the end it will probably save you some money.
Hope this helps.
