Let's say that on draft day, the Celtics pick whoever then immediately announce that they are trading the draft rights to that player, their 2014 first round pick (top ten protected for 2014, decreasing in future years) and Paul Pierce.  (You would have to wait until you select the 2013 pick so that you are trading his draft rights rather than the pick because you can't trade picks in consecutive years).

What is the minimum return of talent that would make you happy?  What is the maximum that Ainge can get in return?

Keep in mind that because the draft is before July 1, you can't do send Pierce out as part of a sign-and-trade because you can't negotiate with another team's free agents before then.  If you wanted to trade Pierce as part of a sign-and-trade, you would have let his contract become fully guaranteed.