Robinson Cano has said that while he's willing to sign an extension with the Yankees, there won't be any kind of "hometown discount". He feels he gave a discount to the team the last time, when he signed for what has so far been a 5 year deal for $42 million (an AAV of $8.4m). Robbie does have a point there, seeing as how he's been worth $107.5 million according to Fangraphs (an AAV of $21.5m).
Not only was he worth more in 2012 than he has in any other season of his career ($35.3m according to Fangraphs), Cano has added a Gold Glove, Silver Slugger, and a top 5 finish in MVP voting to his incredible resume.
Having a 2nd basemen with those accolades is extremely rare to come by, so I think if the Yankees are going to spend on anybody... Robinson is it.