They where willing to swallow Renteria and Lugo's deals. About 30M. They owe Dice-K about 30M in salary. The posting fee is what it is. I'm sure they have recouped some of this already. And I'm sure Tazawa will help keep them up in the Asian market.
It wouldn't be easy. But I don't believe Dice-K to be "untouchable".
In fact the only players on the team that probably are untouchable are Pedroia, Youk, Lester, Beckett and Bard.