If we are just talking about the quality of play, then 700's right, you make that trade every day (assuming it was possible - which I doubt because no-brainers aren't usually true). What has yet to enter the discussion is what salary do you pare to put him on the roster? Like it or not, this team intends to come in right around LT threshold, so in terms of adding elite, established talent, you have to make room somewhere. No Drew? Ok, who plays RF? Crisp is gone? Ok, who plays CF?
It's easy to just sit there and say, I don't care what it costs, but that's not reality. If you want to opine what the GM should do, you need to address all the variables of roster construction. Failure to do that is about the same thing as turning off the "fair trade" button in an MLB video game and romping through a season.
EDIT: For this team to compete with the "no price is too high" team for elite talent in the FA market, they are going to have to have some players making the minimum. Papelbon, Pedroia, and Lester fit that bill, and make this team stronger in the long-haul.