When I passed my test about 10 years ago, I bought myself a 10yr old 1litre VW Polo for £300. I found an insurance company that offered a new drivers deal where you could insure for 18 months, but only paid for the first 6 months at first, then after 6months (assuming you were accident/claim free) you got a much more reasonable premium for the remaining 12months. I think I paid £700 for the first 6 months and then £500 for the other 12 months - a total of around £1200 for 18 months compared to the £1500+ for 12months I was getting quoted elsewhere. Don't know if this kind of policy deal is still available?
As others have said, try and find a car with a smaller engine and I'd also advise against the named driver idea. Not only may it void your insurance and get you in a lot of trouble if they find out, but he wont be building up his own no claims bonus and so you'll have the same problem every time you come to renew. In my experience, insurance companies will try and find any way they can of getting out of paying up if you need to make a claim.
Find the smallest car, the cheapest policy for him and get him building his no claims as soon as possible. And make sure he drives sensibly!!
Also, have a look at topcashback.com or quidco.com - it wont make a massive difference but you might be able to get a bit of money back from some insurance companies when you take out a premium through these sites. Worth a look!