The free agent market is set by the Yankees, and to a lesser extent, the Red Sox, Phillies and Dodgers. If those two teams are not interested in a given player, they come much more cheaply. Conversely, if the Yankees or one of other three let one of their own free agents go and he is not snapped up, then that player can be had for the proverbial song. If the Yankees had shown interest in Jason Bay, then he could have signed for closer to $20 million than the $16 million that he got from the Mets. Anyone else looking at Holliday can probably get him for Bay money, or less.
Assuming that the above is true (and it is), then someone like Damon, such as Damon himself, should be available for a number similar to what Matsui got from the Angels. My preference would be to bring back Damon's bat for one more go- round, with Gardner providing late inning comic relief, and then go after Carl Crawford in 2011. Crawford is Damon's bat plus, with Gardner's speed plus.
I think it would be best if Joe Mauer were left in Minnesota, and let Romine or Monteiro develop.