For on campus accomodation you need to pay for the whole period or at least for 3 months in advance; that is a lot of money. A lot of families who rent out out rooms to the students take weekly payments and it is much cheaper. There is another problem. In off campus accomodation you can cook you own meals and save a lot. For on campus you may have to eat from the university cafe, which is expensive. Also nothing much will be available from the campus shops during the holidays and weekends, which means starvations unless you have your own car.
