Pierce is either gonna get traded, or is gonna be back with the team. The Celtics would be in a much better situation cap-wise riding out the year and letting him expire next year, rather than buying him out this year. Is getting under the tax floor, and gaining back the MLE for one year that important? The direction the Celtics would have to take if they were to dump Pierce would be a team struggling to make the playoffs. I'm sure Playoff revenue for that one extra year offsets the one extra year over the tax apron.
I bet this is Ainge's course of action this summer:
1) Looks for significant trade pieces for Paul Pierce that will both give us potential players for the future, and also draft picks without giving up good cap space position for the future.
2a) if Pierce gets traded, KG looks to be dealt as well or retire's.
2b) Pierce doesnt get traded, stays with the Celtics, KG comes back.
3) Look to deal anyone and everyone that could possibly make a contending team for this year. Either shedding salary, or getting players back. His semi-untouchables: Rondo, and Sully only go in a deal that blows him away.
4) Fill out the roster. Whether Pierce is here or not, if Ainge doesnt shed any of his other salary off this team, there is barely anything he can do with their current cap situation.