SAC
By the time you're training to validate you're supposed to be a big boy and find your own way in life, NATS are your employer, not your keeper.
Any major airport is littered with offers for renting/shariing etc, besides which, within months you'll be earning a decent salary and I really don't see what you are grumbling about, in theory, if you can get through a cadetship you should be able to find somewhere to live.
Back to the original quaestion, if you are careful you should be able to make it through the cadetship at Bournmouth on the salary offered, but I do know of several cadets who have taken part time jobs, either in bars or similar and, by careful balancing of personal and study time, have supplemented their income.