It was only three years ago that Manchester United paid Leicester City £80million to sign centre-back Harry Maguire.
It was a figure that caused some disbelief, with rival supporters suggesting the Red Devils had been ripped off. But the reality is that a valuable defender at any club could easily cost north of £50million in the current market.
Of course, contract lengths and age could alter these prices as demonstrated by Chelsea's summer move for Napoli star Kalidou Koulibaly. A transfer which cost in the region of £34million for 31-year-old.
