Just as a guide, if you self fund look to spend around £15k for aerodrome, £10k for Approach procedural (if required) and £18k for Radar ratings. Thats if you pass first time.
Some regional airports, will pay for training usually after a fairly long period of employment as an Air Traffic Services assistant. Then you can expect a 2-3 year bond after ATCO training, and sometimes thats per rating.
Like you suggest, try the NATS route, it may seem to take a while, but if you are succesful you will be earning far more immediately, and if successfull, you will have a guaranteed position after training (unlike self funding).
As was said before, you can't talk to Air traffic anymore with a mentor, until you have passed the relevant exams at an approved college ( a bloody shame ).
