The TT01 seems to be a favorite starter car for drifters, one of those will set you back around $250-$270 for the car, but you'll still need batteries charger and radio. The RTR kits with a radio will cost you about $350-$400, but i'd advise against that because they come with the stock FM radios.
If you look on sites like www.familyland.com.au
there are plenty of hop us available for the TT01. Ive bought stuff from these guys both online and in store and they are pretty good to deal with.
If you dont mind importing from the states check out www.amainhobbies.com
and for batteries and chargers look at www.hobbyking.com
The car i use is a Kyosho TF-5, i picked it up for on road racing and for drift, but took me a whole 4 weeks to want to upgrade to a 2.4Ghz system. I use a LRP A3-STX radio which cost about $120.
Another thing ive experianced is that it doesnt take long for upgrades that you "need" to add up very quickly on a lower spec car. Hop up parts for stronger components, and power upgrades for longer run times and more speed are common problem areas. So its worth considering spending more and going for a nice belt driven chassis with brushless motor and lipo to start with rather then later. Just last week i spent about $300 on all the gear needed to go to brushless and lipo, because there are alot of hidden costs. Plus another $100 on tyres and some set up gear. This is for a car that cost me $370 to buy at my LHS plus the other $120 on batteries and charger that are now pretty useless.
What part of AUS are you in mate?