Think they'll buy a lot this summer. The deal between Perez and Zidane last summer was not to change the team but revamp a lot this summer if they fail again.
I really think that they will be some big changes with some big heads leaving and some coming.
Kristof Terreur, one of the best Belgian journalist told last week that both Courtois and especially Hazard are looking for a move to Madrid. Courtois's two child are in Madrid and he would like to go back there, as for Hazard he always said that he wants to leave. It's depending on Zidane, whether he'll be on the bench again or not.
Also, Fred Hermel, French Journalist, one of Zizou and Florentino's best frient told last Saturday that Griezmann will be considered this summer and the player is desperate to cross town (and not afraid to betray Atletico)
So plenty of changes for them. Add also in a WC year Perez is always trying to lure the WC best player to Madrid.
They are also talking about Icardi but I think that Griezmann will be their new number 9, with Benzema on the bench.
Then Hazad, Bale, Isco and Asensio on the wings.
Hermel told that Kroos is not fan of Madrid and would like to leave the club if the right offer comes. So I also think that they may buy a midfielder too.