I don't like Cameron's piece on this at all:
http://www.fangraphs.com/blogs/mariners-break-the-bank-hope-robinson-cano-defies-odds/
I don't like the comparison to the Royals and the James Shields move. The Mariners didn't lose a stud prospect in acquiring Cano. Moreover, he overlooks the need to rebuild the value of the franchise. If Cameron was in charge of the Mariners, he would probably run the organization into the ground.
The Mariners might be closer to winning than he thinks. They have the arms in the rotation and some intriguing position players.
In the larger picture, value is a difficult concept to quantify. If Cano mobilizes the fan base, and helps the organization win a championship, the contract makes eminent sense for the organization. While I'm a strong believer in building a strong farm system, expensive free agents are often indispensable components of championship-winning teams.