Because big scholarships are not going to happen at medical school on a very regular basis. For the most part, you can expect up to $5000 per year, which probably won't sway you too much. This isn't like undergrad where people are fighting for you, as there are enough qualified people willing to take a spot and pay full price. Yes I know, people do get full-rides, but these are given to a very few select people and by only a few select schools (Pitt, WashU, Yale come to mind), often before the financial aid packages are given out.
As for loans, they are all going to be the same regardless of tuition. Tuition + $15-20K for living expenses (with variance due to cost of living in that city).