@Daria B. I would think condos or houses with rooms rented to grad students will cashflow more.
I once rented a room and shared a bath on Archer Rd for the same price as a whole two bedrom apt further from campus. With both myself and my roomate paying that rate the owners were propsering. It was a condo.
A lot of the buildings that look like apartment buildings are really condos being rented by the room to students, with a centralized property managment office that owners can opt to use.
Most of my law schoolmates rented rooms in houses across the street from campus. I think in a college town the house or condo room rental is the way to go unless you're targeting school staff and professors. Folks unrelated to the university are living much further away in suburbia, own their own place, or can only afford the D class homes you've mentioned.
It's not uncommon that getting a cheap rental property goes hand in hand with accepting Section 8 in Gainesville. This has been my experience and learning from some investors and the REIA group up there. I dont know if much has changed since I left.