The one thing I have learned about university costs from MN is that a lot depends on the student themselves.
DS is naturally frugal. He cannot see the point of having more than two pairs of jeans, a jacket and half a dozen T shirts. He hates shopping, but really enjoys things, like reading around his courses or attending public lectures. He is involved with student societies etc, but expenditure seems limited to group outings to Chinatown with the nearest available Chinese speaker ordering from the cheap student menu. There are quite a lot of overseas students in his friendship group, and often they cook and eat in groups. He has also taken to making sandwiches and bulk cooking and then using the freezer, which I had not expected.
That plus landing a paid internship last summer, and hopefully another one this, means that his costs are relatively low. His rent is high because he is in London, but mitigated by the fact he does not pay fares or run a car. (Which to my surprise, students elsewhere seem to do.)
I doubt DD will be as cheap, but she has been earning through her gap year so it will be up to her to fund extras vodka.
Several posts on previous threads seem to suggest that students are hard done by if they don't have lots of cash in their pockets to spend on non-essentials. Fine if the parents can afford it, but otherwise I don't think parents are obliged to help fund their child's social life. London in particular, but probably elsewhere, it is quite easy to pick up additional, not too demanding work. Tutoring, waitering at Christmas events, a session or two each week as a life guard.
Not having children in the house has reduced our food expenditure by a surprising amount.