Kinsler makes, 16M, 16M, 14M, 11M. Prince makes 24M for the next 5 years. Obviously year 5 is huge 24M vs 0 (if they dont resign Kinsler). But this isn't like some huge salary addition/subtraction for either team. I saw (not sure if true) that Detroit is sending 30M to Texas on top of it. If so the difference in total money averages out to around 7M a year in savings for Detroit, which is around 5% of their yearly payroll.
Kinsler is also 31, Fielder 29.