I think it would come down more to what would we have to give up for Cousins, to see what would be left for Durant and Cousins to work with. If I'm the Kings I'm looking for young talent and draft picks, if I'm the Celtics I'm not willing to give up Brooklyn pick this year even for Cousins. So with this in mind, something like this would work, with both money and picks. Do I think it gets it done, no but it's what I think is worth for Cousins because of the history of Cousins. Personally I don't think Cousin is coming to Boston.
Tyler Zeller
Kelly Olynyk
James Young
Terry Rozier
Jonas Jerebko
2 of the 2016 1st round picks (not including Brooklyn)
2 of the 2016 2nd round picks
In return we get Cousins. They get Olynyk for another year, Young for two, Rozier for three, Zeller expires, Jerebko for a year or can not keep him. Plus they gain two mid round 1st and 2 second round picks.
I think if we do this trade we should resign Jared Sullinger and Turner to respectful contracts because both hold the value for us. Amir Johnson we let go and resign but not for the 12 million he's getting next year, I'd be willing to do 2 year for 12 million. Sullinger I'd be willing to give 4 years 32 to 36 million. Turner I'd be giving 2 years for about 8 millions. By doing this our team looks like this.
Center - DeMarcus Cousin, Amir Johnson
Power Forward - Jared Sullinger, Jordan Mickey
Small Forward - Jae Crowder, Even Turner
Shooting Guard - Avery Bradley, R.J. Hunter
Point Guard - Marcus Smart, Isaiah Thomas
Keeping Brooklyn's pick we hope we get Ben Simmons. By simply adding him we wouldn't need Durant with this team above. But we'd get Durant's attention because Simmons can play SF and PF. If we don't get Simmons, Skal Labissiere or Brandon Ingram would be great additions. With the later first rounder I'd want to be able to draft Damian Jones the center from Vanderbilt. In the second round I'm looking at AJ Hammons from Purdue. Jones and Hammons would be great back ups for Cousins. With the second 2nd round pick I'd be aiming for Michael Gbinije.
If we get Simmons I rather not go after Durant and just keep building young an reward the players we have.