there is no guarantee here that they will win anything, even if they buy new 11 top players. I remember when Real have Figo, Zidane, Beckham, Ronaldo but he still not win many trophies.
Also, how much players they can buy in one transfer summer? He already spent 300million, if he doesn't sell someone, how can buy more expensive players and stay in FFP? Plus he asking too much money for his players even if they don't play on the top level.