Source, don't be put off by the batteries and other costs comparisons from on road to off road. If you are a noobie to the hobby, have a look around at the clubs in your local area, when they meet and how they fit to your schedule etc.
You will have fun running anything from a Mini to a full on 4 wd off road buggy, but keep in mind that you will have to work to your budget and how far you want to travel to go to race meetings etc.
Please feel free to drop me a line at AARCMCC and I can help you get in touch with some of the clubs in the Sydney.

Peter Ellis