I agree that the Red Sox had a salary dump by unloading big contracts, and didn't have to pay any portion of them. However, this deal is more of a salary exchange for the Rangers. The Prince deal includes another overpaid player in Ian Kinsler.

I believe that Detroit is chipping in $30 million to help pay for Prince. That would bring his deal to $138 million over 7 years.....coming to $19.7 million/season.
Kinsler has 4 years left at $75 million....$18.7 million/season. It's practically a wash.

Therefore, assuming my math is correct, the Rangers will only be paying an extra $1 million a season for the next 4. The final 3 seasons with an overweight Prince will be a bigger question mark. The Rangers supposedly came in second for Prince a few seasons ago, and this should be a much better deal for them.

Finally, the Rangers are going with their prized prospect at 2nd. And the Tigers have the All Star Kinsler at 2nd. Thus, I don't expect either of them to be in the Cano sweepstakes, despite what the media reports.