Upvote:2
This kind of question is difficult to answer because we don't really know what you want or expect from your hotel. It is possible to economize in Oxford but you may find you are in quite a downmarket kind of place.
If you are paying yourself, I would say that the hotels are quite expensive for what they offer, even compared to central London for example. I think it is simply a lack of competition in Oxford. So yes the prices are naturally high.
Maybe you can save money with Air BnB. If you stay in a place far away from the town centre, there is plentiful public transportation and cars are really difficult to use in central Oxford.
If you did not study at Oxford/Cambridge, it might be worth staying in the college accommodation to try it!
(Oxford University has no campus, the University and college buildings are spread out all over town.)