I would listen to what your parents are saying about the finances. If they say they can afford Middlebury and you like it best, go to it. As a parent who is able to be full pay with the 529, our savings, and eventually a home equity loan, it was important to me that my son go to the college that was the best fit for him. At one point when he was talking about wondering if he should save us money, we were very adamant in our reply that we had worked and saved all our lives to be able to send him wherever he might want to go, and that it would negate that effort if he chose his college by price.
He now is at a college similar to Middlebury, and it is worth every penny to us. He is thriving in that intellectual environment with brilliant peers. Comparing his experiences over December and March breaks with those of some of his friends who went to different types of colleges, there is no doubt in his mind that his is the best college experience for him personally. It seems like a different world from some of those other colleges. Although one can go on to do great things from any of your choices- it is the person more than their college that determines one’s success in life- Middlebury will be a great experience not only for its superior reputation but also for the learning experience it will provide both in and out of the classroom. The “long term benefits” will include how you think and write, and how you view and contribute to the world— even more than how much money you will make.
If the fit for you is better at UVM or St. Lawrence, then go to the best fit college for you personally, and you will thrive. Those are very good colleges, too. Middlebury is not the best college for everybody; some would enjoy another college more. But if you are a “life of the mind” type of person yearning for a school like Middlebury, and your parents say it is manageable, you should take the opportunity to go there.