It really is tough for young people (and young men in particular) to get affordable car insurance. I don't know how the rules compare across countries, but I've learned the following here:
1) Price depends very much on age of the driver, location, and type of car.
You can't do much about the first two, but you can definitely affect the third. Before you buy a car, get some quotes from an insurance company for three or four different models (same year). The differences can be quite surprising. (I've never bought a car without knowing its relative insurance premium ahead of time.)
2) You can bring down the premium by increasing as much as possible your deductibles. Set them to as much as you could afford in the event of an accident. (This is a good policy for insurance anyway.) Put aside the amount you save into a bank account until you can cover that deductible.
3) Some companies here offer a "good student" discount for having good grades at school. Have you asked about that?
4) You can bring down the premiums by 10-15% by completing an advanced driving class. It's worth considering for the long term.
Other than that, drive carefully. The longer time goes by without an incident, the better deals you'll be able to get.