4. Cristiano Ronaldo | Value: £70m
Cristiano Ronaldo still scores at least one goal every game but, because of his age, his value is beginning to slowly decrease.
The Real Madrid superstar turns 30 next February, so there’s very little chance of any of the world’s richest clubs agreeing to pay Los Blancos over £70m for their most famous player - particularly when you consider how much the Portugal captain would demand in terms of wages.
No other 30-year-old could fetch a transfer fee close to £70m, but then Ronaldo is no ordinary footballer. He is at his peak right now - but how long left, realistically, does the prolific two-time Ballon d’Or winner have left at the very top?