Are you male/female.. under 25?
Just car is the cheapest we've found ($600 annually) but that's because my partner is male, under 25 and had written a car off previously.
The other one is NRMA $40 a month.
It all depends. Don't go to Shannons, if you claim you're a car enthusiast but are under 25 yrs of age, they won't take you seriously.
Hope that helps!