I will start by saying I'm biased as I got the A from Tufts and R from BU; however, I don't think there's really a tangible difference here. I'd say big picture, these schools are interchangeable, though BU might have the edge in terms of research. Also, Tufts incorporates into its mission a focus on serving underserved populations. I do not believe BU does, which makes sense since I feel a focus on research vs public health tends to have an inverse relationship. I think you should absolutely take the cheaper option. If cost isn't the deciding factor, then perhaps you get more nuanced and compare which curriculum u like more, what you thought of the student body (personally, I've consistently heard Tufts is very laid back and the students there are happy) etc. Big picture-wise I give BU a slight edge due to more ongoing research, but go Tufts if you want a focus on public health integrated into your training. Best of luck!