Depends on who's playing what in front of them. I believe the ball playing defender role was born out of the situation Conte was in where he wanted to control the play and took advantage of the fact that Pirlo was heavily marked in every game, not because of the number of defenders.
I don't care how many defensive mistakes he makes, his long balls are better than Pirlo's and are crucial to our attack. Eliminate Bonucci and we got nothing. He's our Payton Manning.
The only way you'd get that much for him is if one of the rich clubs took an interest (i.e. Jovetic - City). No regular club would pay that much for him. Jovetic was also better known at the time.