If you are any good at a technical subject i.e. maths/physics etc then you can quite easily get a very good return on investment.
I did a 3 years Maths degree at a red brick, and within 6 months of graduating I got a job in one of the city Investment banks.(despite not even getting a 2.1 or being on any grad scheme)
I'm now 26 and in that time I have paid off a 12k student loan, saved up the funds for a modular course, got a PPL and had haven't had to skimp on spending money.
Despite the economic conditions there is still plenty of hiring going on in the city, just not in the credit/mortgages businesses. Especially if you have a Maths/Physics based degree.
However if your going to get a non specific Humanities degree or similar, then I wouldn't bother.