Dybala should be worth at least 150 million, if bums like Coutinho and Dembele can go for that amount of money; Dybala is an established player in a top club. Obviously, we shouldn't sell him, but if Mbappe is coming in as a replacement, then it'd be very difficult to say no to a deal of that magnitude.
Pjanic is an 80 million player. Benatia won't get you more than 20, Pjaca another 20, and Higuain 30. We'd be lucky to get 10 for the Accidental footballer.