I'm surprised more don't go to a local college, rather then in another town.
But it depends what level of university you are aiming at. Most people don't live within commuting distance of a top 10 or 20 university and a degree from your local middle or low ranked university is not equivalent to a degree from a top university, even if the subjects are the same.
In any case the fees everywhere are 9k per year (and will increase from next year at most places). Students living at home will have expenses of at least several k per year and are eligible for student loans for these (although less than those who live away from home). So staying at home would still cost 35k+ for a three year degree. The extra 15k needed to live away from home could well be worth it if the course you choose is significantly better, because in any case you repay the student loans based on a percentage of income - it takes longer to repay the loans if you borrow an extra 15k but you don't pay higher monthly payments.
I would myself encourage my own children to think about going to our nearest universities and living at home, if they were looking at comparable ranking institutions away from home. But I wouldn't encourage my kids to go to a local low ranking ex-poly over Oxbridge, Durham, UCL etc just to save money in the short term.