we got him for 20mil, but they have a buy back clause of 30mil that they can exercise anytime they want in the next 2-3years, that wont change, regardless of the players growth (unlike what Parma did to us with Giovinco)
We can both agree to sell him to a third club, but for a higher clause.
In a few words, if the player flops we lose 20mil, if he turns into real starter material or profit maker, Real can reinvest 10mil, only when they will be certain for their profit.
The path to convince the player to sign everything, is dramatically increasing his salary.