Start small, my friend. No experience doesn't sound brilliant for a complicated bot like the one you're suggesting, do you have access to tools? Welder?

And small budget, well, with about £200 (very, very cheap) I've managed to collect the parts for a simple first time push-bot, powered by the cheapest of everything, that being drill motors, electronize ESCs and the cheapest transmitter-reciever in existence.

If everyone could build the Chaos 2 of their dreams first time, this hobby wouldn't exist! :P