The way I see it, university is worth it if you love studying and know you won't be happy unless you're working a job you love. With debt, it's entirely worth it. Not only will you not pay back the full amount because very little people do in under 30 years, look at it this way.
If you get a job which you love and it provides you with a nice house, a nice car, or holidays or whatever else and the comfort and security in life, then paying back very little each week won't bother you. & if you don't get a well paying job, then just know you won't be paying back the debt at all. You won't get rent collectors at your door taking your things out your house if you don't pay it back. It's all down to whether or not you enjoy studying, learning new things and a specific subject you want to major in in life and therefore work one day in the industry of your chosen subject. It entirely depends how bothered you are by what career you get out of it in the end. You also have to take into consideration though that a degree is worthless at times if you don't do work experience, build up your CV and do internships. These are so important to employers and both work experience and a degree will make you stand out in the crowd.
University isn't like college or sixth form where you work for it then get your A levels then automatically get into the university of your choice or wherever else does your course. You have to have structure and build on the building blocks as a person and on your CV to come out of university and do well. This may not apply to all degrees, but most of them.
Take complete advantage and grab the opportunities university provides. Whether it work experience, or travelling with your societies, or just the social scene in general where you make contacts and meet people who inspire you to do well in life and go down other paths in academics to better yourself and better your horizons. It costs 9 grand a year, so go out there and don't ignore the help university provides for you to do well and all the opportunities it offers that no where else does. University is only a waste if you do something because you believe it will be a fluke and you ignore what the university can provide for you both in employment and in life. Go in there with all guns blazing and you'll have an incredible time.