I don't think that it's worth it to the Sox to acquire Lee, but I don't think you're correct on a couple points.
1. That the Mets won't include money to trade Beltran. No one will take on his contract in total, even if the Mets give him away for nothing. In order to move him, they will have to eat a chunk of salary, making it close to Ordonez's salary.
2. That a trade for Beltran+Lee signing puts the team in a worse position than just acquiring Ordonez and Lee outright. The pieces in the Beltran trade are either Matsuzaka or Scutaro - assuming Lee is signed, he fills in Matsuzaka's spot, or if Scutaro is signed the Sox break camp with Lowrie as their shortstop.
Theo seems reluctant to move Dice-K, though. I think that, if he can't get a suitable RH OF, the Mets would move Beltran and $6-8 mil for Scutaro. It fits the needs of both teams perfectly. Mets need a 2B and money off the books, Sox need a RH OF bat.