Cavani and Isco are pipe dreams. They will leave for 50M + offers, demand stellar salaries, and will probably choose leagues considered to be more attractive.
We should focus on retaining our best young players, and keep growing steadily. We will have to increase at least the salaries of 3 of them (Pogba, for staying, Dybala, for the season he had, and Morata, also for staying), we will have to pay to keep Morata. It's not going to be much money left if we keep these guys.
Priorities:
1 - Keep Dybala
2 - Keep Pogba
3 - Keep Morata (paying 20m for him should do it)
Also, I feel we are obliged to invest in Berardi. We just can't let the opportunity go. He has to be signed, and that's another 25M. Even if he fails completely, we can easily fetch back 60 or 70% of the value in 1 year. He will have to work out as a SS.
Cuadrado, I'd like to keep him, but I'm pretty sure we don't have an agreement for his price and Conte won't let him go, no way. So no Cuadrado, replace him with Berardi.
As much as I love Zaza, 5 strikers with Berardi will be just too much. I'm afraid we'll have to sell him so other positions can be improved. He'll have suitors from EPL. Neto is also a guy who has value and can be sold to make some money. I don't think they really consider him for Buffon's replacement.
In: Morata (20M), Berardi (25M), Lemina (10M), young promising AM/creative CM (15M), Vrsalko (15M), Tonelli (12M), Marchetti (free).
Out: Zaza (25M), Cuadrado (end of loan), Hernanes (free), Caceres (free), Neto (10M).
Net expenditure: around 60M.
Starting team: the same as today's - 352. But rotate much more next season, play Rugani, keep midfielders fresh.
Bench: Marchetti, Vrsalko, Tonelli, Rugani, Evra, Lemina, Asamoah, Sturaro, Pereyra, new AM/CM, Berardi, Morata.