Yeah, agree with other posters about price. Beyond cost of attendance, I'd also consider cost of flights/travel to and from the interview.
For more personal preference things that are irrespective of cost, you might think about:
- Class size and composition (not only in regards to what you're comfortable with, but also in regards to your relative likelihood of acceptance - interviewing for a school you only feel okay about that only accepts 10-20 OOS students may not be a great choice compared to a similar school that has more OOS positions)
- Location
- Academic nuances (PBL vs non-PBL, 2+2, 1 vs 2 semesters of anatomy, that sort of thing)
- Type of interview (I love MMIs and think I would have done those over open file interviews any day)
Again, these are just some things to think about, though I still think your first and foremost consideration should be cost of attendance. But, if weeding out for price leaves you with a few conflicting schools that are very similar in cost, these might help you sort out which interview to choose as well.