For another comp, here are Carlos Santana and Victor Martinez (at the time Martinez signed a four-year, $50 million contract with Detroit in November 2010 a month before his 32nd birthday):
CS 1116 G, 4782 PA, .249/.365/.445/.810, OPS+ 121
VM 1004 G, 4224 PA, .300/.369/.469/.838, OPS+ 121
Santana, who turns 32 in April, and Martinez are switch-hitters who came up as catchers with the Cleveland Guardians before converting to first basemen/designated hitters.
In November 2014 Martinez signed a four-year, $68 million extension with the Tigers.
Santana this year ranked seventh among first basemen in the Fielding Bible voting, two slots behind Mitch Moreland:
http://www.fieldingbible.com/complete-votetally.asp