My friends brother is having the same problem. He's 17, just bought himself a 1.1 corsa which he has been learning in. The car is kept on a gated driveway in the village which is in the middle of nowhere and the cheapest quote he could get was around £3000.
I think the two main factors at that age are location and occupation.
It is getting ridiculous though. My insurer last year bumped up my insurance by £400 for no reason at all. The only thing that had changed was I had earned another years no claims!?