He's one of the only guys I'd ever even consider paying that much money. He just turned 24 and already has multiple all star appearances, a batting title, world series ring and before turning 24, racked up 125 homers and has been on base over 1100 times.
He had a "down year" last year and had a WAR over 5 and OBP over .400. Plus, I imagine the banning of the shift and the potential for automatic strike zone will help a guy who has one of the best eyes the league has ever seen.