The Houston five year deal with Cristian Javier, along with Miami's deal with Alcantara last year, set some parameters for an extension for TMac. (Both are/were better than TMac at the time of their extensions.) At the time of their extensions, all three were about the same age.
Javier is a Super Two, which TMac is not, and that makes a difference. Alcantara's contract contains option years, which Javier's does not, and that makes a difference.
So, depending on the inclusion of option years, an extension for TMac that would buy out two years of free agency should cost somewhere in the vicinity of $60 mil.