The New York Yankees' deals with Jacoby Ellsbury and Brian McCann both made a lot of sense -- premium players still in their prime years at premium positions with positive defensive value. If you're going to go bananas in free agency, with money or years, those are the guys to go after, because unless they go all B.J. Upton on you they are better bets to hold their value and give an adequate return on your investment.
Three years and $45 million for Carlos Beltran doesn't make the same kind of sense. He's a possible Hall of Famer and still a potent hitter from the left side, but the Yankees just signed him for his age 37 through 39 seasons even though he's showing signs of decline and is probably best suited to DH, if not right away then certainly before this contract is over.