I wouldn't be asking yourselves 'who is the cheapest?' I would be asking who is the best 'Quality' Training provider..
Flight training is not cheap you'll have to accept that if you want to do it.
I would suggest if you want to save a few quid, do a modular course, initial flying in the USA or Australia is cheaper than the UK and quicker. Go to either Oxford or Bristol for your groundschool (I wouldn't even consider anywhere else), and finish your CPL and IR with a good value school in the UK (plenty around eg: Stapleford).
If you pay the turks peanuts i'm afraid you are going to get monkeys. Good luck.
