If Pierce could be convinced to 'opt out', what sort of new deal would he get?

[Brickowski]

I believe that the Celtics still have Bird rights if Pierce declines his player option.  But his salary stays on the cap as a cap hold.

If the Celtics want to get rid of the cap hold, they must renounce him, and in that event they would lose their Bird rights.

Pierce isn't playing well right now, and we don't know how serious his knee injury is.  He will probably have more bargaining power next year when he's healthier, which is another reason why he should exercise his 21.5 million-dollar option.