Accommodation is definitely more expensive (and almost all catered - only one or two colleges offer self catered, not the one DD applied to!) but they offer generous accommodation grants and other grants/bursaries/scholarships because of the collegiate system, moreso than Newcastle from what I can see. Her pros/cons lists so far have been -
Newcastle pros - lovely city, lots going on, lots of friends/familiar faces, good module choice.
Newcastle cons - possible too many friends/familiar faces (everyone around here goes Newcastle or Northumbria), module choice not quite as flexible as Durham in later years, cheaper cost of living.
Durham pros - good module choice, enough friends/familiar faces but not too many (2 of her 5 close friends there will be graduating this year, though one is planning on staying to work at the university), a very student-oriented city, good module choice, good bursaries and student support.
Durham cons - less metropolitan, less going on, very white, southern & mc, potentially too much module flexibility(!), more expensive cost of living.