Bunting is 28 years old, signed for 2 more years at $4.5M. It seems Dubas really likes him, as he's one of his wins in Toronto. His assumption is he fit with Matthews/Marner, so he'll fit with Crosby the same way.
He was too expensive for what he brought to Carolina (3rd line winger for 4.5M), so I would think he had negative value for them.
As for the prospects:
Koivunen - 2nd round pick (#51)
Ponomarev - 2nd round pick (#53)
Lucius - 4th round pick (#124)
So basically we gave up Jake + a 1st rounder (Ty Smith) for:
Bunting
3 x 2nd rounder
1 x 4th rounder
and a conditional upgrade to 1st + conditional 5th rounder
I'm really surprised he didn't get a no-strings-attached 1st rounder draft pick out of this.
My biggest concern is what Sully will do to these guys
.