@Cassi Justiz good point about overbuilt rentals. I graduated from Auburn University. I don't know the exact statistics on how many rentals were built, but massive property management companies came into town and built large apartment complexes. Meanwhile, the university was capping enrollment and not expanding at the rate at which they were enrolling. Maybe by 1000, but not at the rate that the apartments were being built.
With that being said, majority of the people I knew that lived in those apartment complexes did not stay in them more than one year. The newly built complexes were thrown up quickly and had a lot of issues with them. I'm sure it changes campus to campus, but upperclassmen wanted to live in houses off-campus. The houses within walking distance seemed extremely overpriced to me, but people will pay for it.
I have talked on a couple other forums about this topic. It is interesting and definitely varies by campus!