Balotelli is the only really good player in that horrible squad. They have nothing else. Milan would be crazy to sell him, despite all his bullshit.
I'm sure a lot of teams would be willing to pay 30M for him right now.
As a player he would score 40 goals a season in Juve. But it's impossible to imagine him with us, he's just not Juve's material in human terms. But he's still young and if one day he end up with us, it would be very interesting.