GFXman is right - Just Cars (and probably all the others too!!) have all of these "additional excesses" on top of your base excess.
For example, my excess is $600, plus $400 "age excess" because I'm under 25, plus a $600 "import excess" for who knows what reason. Plus theres a $1,000 "theft excess". I'm happy to pay the $1,600 worth of excesses as long as my car is fixed or I'm paid out my agreed value in case of an accident.
The only problem I have with my policy is that if my wheels get stolen for example, they are covered for $2,000 - by the time I pay all of the excesses (minus the age excess) I could have practically bought another set of wheels...