Thanks everyone. We managed to get a quote for £1800. This is for a Rover Mini Cooper 1.3i which we already had and which I thought would be too expensive to insure him for, but it ended being the cheapest!!!
I do feel sorry for him though, as now that the car is taxed and insured, I won't let him drive it because of the weather. He's a good boy though, as he understands that there is no way I will let him have his first experience of driving on his own with snow and ice. Poor boy :-(