I think you just need to make sure that you minimise your risk as much as possible as a provisional driver, make sure you have a small engine, go for an older car so if you have a knock or 2 you won't mind covering that cost for small repairs while building up no claims bonus, and your driving experience.
Seriously consider taking out comprehensive insurance for the first year, even if it is significantly higher costwise, if you do any reasonable distance annually.
It will be expensive for the first year, but do the Ignition course and it will help to bring the cost down.
Ring around all the companies / brokers and see who can offer the best deal, not all companies will cover you but a number will, Ladystar / quinn / hibernian are the ones that spring to mind.
Most of these companies will let you pay monthly (ok you pay somethign like 5-7% extra for the privilege, but it is handy).
Apply for your driving test now, it may be 30-60 weeks until you'll do it, but it will make a difference for you financially (from memory, when I got mine in first year of driving I got a refund for approx 15% of the years cost, that was in month 9 of the first year). Your priority should be to get your test, I don't understand why people are happy to drive around 5-10 years later on a provisional.
If the cost is really prohibitive, wait and save for another year, I'm sorry to be the one to break this to you, but once you get a car you no longer have any money!!!!