Number one reason for choosing a school should always be where you think you will be happiest. For some people the burden of loans will negatively impact their happiness, for other's prestige or location of a school can trump the burden of loans in terms of affecting their disposition.
The hard part is always deciding how much money is too much. However, for me, because I've come from a career where it was all about sacrificing too much of your life for money, I refused to continue the trend when I switched to medicine.
In the end, Dartmouth is still an Ivy and has the networks and endowment to support a wide network of global and domestic opportunities. Sure the difference in ranking, curriculum and training may be comparable to your state school, but Dartmouth has renowned resources in particular to things like global health and policy work such as at the Dartmouth Institute. Is that stuff worth the extra cost to you? If that's going to be your career, it might be, if you don't care for that stuff however, state school will make you an equally great clinician.