Negotiating 101. Ask for way more than you'll get. I suspect he'll get 6-8 years at 20m or so. Owners/GMs have to look at the deals like A-Rod/Hamilton/Pujols and say "You know, when players hit their mid/late 30s, they're just not worth that much." There's no reason for the Dodgers to pay Cano for what he did with the Yankees.
Of course, it only takes one Tom Hicks-type to bid against himself. And the Yanks did the same thing, again, when A-Rod opted out of the bad deal Hicks gave him.