IMO, the choice of whether to go to Uni should be partially based around what you see as your future career (and yes, at 14, that's too young to make that decision). It's worth viewing it as a financial investment (which it is).
If you want to do a job for which a Degree is not a necessity, then you're almost certainly better off not going to university, and spending the three years in a job, gaining valuable practical experience - you'll be earning money, if you're good, you'll be at a higher pay/career level than graduates by the time you would have finished Uni, and, crucially, you have a job (and even if economics leads to redundancy, you have the experience to get another job). Added to which, you also don't have a ridiculous loan hanging around your neck. How the employment market will be in 7 years I don't know, but its ludicrously hard at the moment, with so many graduates looking for jobs - any degree you do undertake, you're gonna need to be in the top 25% of marks, or it will have been a waste of time. Note, rather sneakily, that many firms have started asking for 1st year results, even in degree courses where these results don't count towards your final mark (and one firm I looked at stated point blank that if you had got more than one 2.2 grade in any given year, they would immediately discard your application). In some of the professions, there is also a large Oxbridge graduate bias amongst many firms. So choice of uni matters massively too.
If you DO need a degree for your proposed career, then sure, go. Primarily, the careers that require degrees also pay the best, so whilst the loan may seem large, it will be quickly dwarfed by your pay when you do start earning.
If you're in one of the in-between careers, where going to uni actually does lead to an advantage, it's worth bearing in mind a number of things, primarily that depending on the career, there are scholarships/funding available. A friend of mine obtained a contract with a civil engineering firm before he started uni to study the subject, and they paid his course fees, gave him a generous grant, and gave him the option of doing 2 months work every summer (for which he was also paid). Then you don't a loan. It's an option, and it's worth investigating.
Bear in mind that not every uni as expensive as the others, and that applies equally to fees and to living costs. Cardiff is the cheapest university city in the UK, and living costs over the 3 years are over 50% cheaper than going to a London-based university.
You're also probably being naive if you think that a future government will reverse the decision - once the increase has been swallowed by the public, there's no way a government would REVERSE such a measure - the state of university finances in the UK has been dire for a number of years, due to inadequate funding.
EDIT: Finally, its also worth realising that 18 is not the only time you can go to uni. If you need to work for a year or two, to offset the debt, that's probably a good idea...
So I say go for it!
