They may pay it if Matsuzaka agrees to a low-ball contract. Many people were predicting a 5/50 deal for Matsuzaka with a 20 million posting fee. In essence, 5/70 or 14 million a season for him. The Red Sox may have bid 45 million, but only plan to offer him a 5/25 contract or a 5/30 contract. The total cost would roughly be the same. They may feel it's worth the risk. I have heard a few times Boras is going to want 3 years max on the contract. So a $45 million posting fee is more difficult to justify when the agent's position and starting point is known to be 3 years. Remember, whoever wins the bidding has Matsuzaka's rights for 6 years, regardless of the contract he signs. They could have a clause put in like the Yankees did with Matsui that after a 3-year deal, the team is contractually bound to non-tender him. Of course, the Red Sox could still resist those demands and allow him to go back to Japan. Furthermore, if Boras has said to be telling teams he wants a 3-year deal, that may have been why there were rumors of a low posting fee.