When discussing issues about the 'market value' of a certain player, many of us seem to disregard how 'young age' not just increases the overall value, but does so in a dramatic fashion because of the element of 'potential'. Clubs gamble on possibilities, raising valuations well below the actual 'worth' of the player, one that in real life is governed factors like player's quality, playing position, marketability, resale value, the League, the Club and the nature of the player's contract (existing and new). When playing for Juventus, Pogba was extremely young (only 22), and hailed as someone who could go on to be the best midfielder in Europe (the aspect of potential).
Pogba hasn't proved to be half the footballer people thought he would be. At his age, he should be at the prime of his football career, and if this is his prime, then Juventus have managed to put one across United by selling him for £90 + million. Clubs will no dish out extra on the element of 'potential' if they try to secure his services. He will definitely improve with the right kind of nurturing, but will certainly not reach the lofty heights people imagined while he was still playing for Juventus. The occasional histrionics and perfunctory attitude hasn't helped his overall brand image. And he is on a whopping £300,000 a week. Many people here will be quick to point at Mourinho's negative tactics for all his failings, a notion that I am not willing to buy.
United will be lucky if they are able to recoup around £70 million for him, if he is indeed sold in the summer. Pogba will be 26 years in three-months time and no longer a 'young' player.
(P.S. I don't think Pogba will be sold in the summer).