Panama has gotten more expensive since I was stationed there in the latter half of the '90s but your dollar should still go a lot further there.
Unless you live at elevation though, Panama is even hotter than PR. Also, Ashford Hospital in Condado, PR is a very good hospital - better than anything in Pma or CR.
Depending on if you want to live at an elevation with a very pleasant climate but not on the seashore, I'd investigate Boquete and Vulcan in Chiriqui province, Panama. I'd also consider PR, of course. PR has better and more convenient air connections to Mass., naturally. I guess it just comes down to what works best for you.