Not sure if it's too late but Real Madrids former canterano Dani Carvajal is a great purchase. You have a buy-back clause and he can come in and deliever straight away. Besides that you don't need to strenghten anything the first season, but you can spend the money on promising youngsters. Later when you come to January you will pick up some extra transfermoney so you should take a look at players like Leon Goretzka(Bochum), Pedro Obiang(Sampdoria), Ruben Pardo(Real Sociedad), Inigo Martinez(Real Sociedad), Kurt Zouma(St. Etienne), Ilkay Gündogan(Dortmund), Mario Götze(Dortmund), Isco(Malaga), Gareth Bale(Tottenham), Alen Halilovic(Dinamo Zagbreb), Alvaro Vadillo(Betis), Julian Draxler(Schalke), Rodrigo Moreno(Benfica) and so on...
Might be because I'm a huge Madridista but I always find my Real Madrid saves amusing as I can make a "challenge" for myself in the save. Like only buying youngsters, only using canteranos, only Spanish players etc.