OP you are well-spoken and thoughtful in your consideration of the pertinent issues, imho.
I think an extra $10K per year is worth it, for a school that is a particularly good fit and where you or your parents are not taking on extra debt. We would do that for our son, without hesitation.
It is probably a wise move to make the trek to WPI for an accepted students event, should WPI be in the top 1-2 choices!