We also need to be thinking about marketability. Morata isn't that marketable. If we're going to invest 50+ million in a player, that player had better bring more eyeballs to Juve, and sell more shirts. Not only is Morata hardly a 50 million player, but he has average marketability. Compare that to Paul Pogba, where you have celebrities wearing his kit. Balotelli also had huge marketability, but unfortunately he was a tool. This is one of the reasons I advocate for James Rodriguez - he has a monopoly on the Colombian market, is young, a true gamebreaker (watch the Coppa so far), suits a positional need, and is a gamebreaker. There are no other players who could be feasibly purchases and could be available with that kind of talent and marketability.
If you pay that kind of sum for a player:
1) It shouldn't be a prima punta, rather a seconda punta/ trequartista, due to the ability of the latter to improve players around him,
2) He'd better be marketable, which Morata is nothing special
3) A sure-fire first teamer, which is difficult when you have Mandzukic ahead in the depth charts.
If Madrid will take Morata + 35-40, spread over 3 years, you do it IMO. The marketability of Dybala, Rodriguez, and Pogba could really do a lot for the brand.
If fact, it is rumoured that despite Zidane not wanting James, Perez simply wants to retain him for his marketability.