It says by telephone, does that mean it was all landlines then?
Pollsters can dial cell phones - if they have a live interviewer.
Live interviewers are expensive because you have to call bunches of people to get people to pick up, let alone not hang up. Autodialing is a lot cheaper because can dial lots of numbers and have a single computer handling several calls at once.
It is possible that it is cheaper for universities since they can hire students for minimum wages for a part time job and maybe some class credit. If you were hiring in the regular workforce, you would probably have to pay more to get competent interviewers, since they would be more interested in regular income, as opposed to some extra cash.