I do think one of the problems we have shifting players is the way that the press continually downplay and denigrate our players. Many of our players get ridiculous mounts of criticism compared to certain other teams that play in red, and this impacts the perception of our players and the price we can get.
Example, just seen an article on rumour of Managala to replace Wimmer ar Spurs, and the Spurs fans calling him a clown/liability etc, but there were stats in there showing Mangala winning way more tackles, ariel duals, interceptions and having same pass completion rate.
Same goes for Joe - he is far and away the best English keeper over the last 10 years, is a current England International and has not suddenly got worse overnight. Apart from the fact he doesn't fit with Pep's particular style he would not be moving. Fans of other teams would no doubt welcome DeGea, and yet slag off Joe who I feel is as good an all-round goalkeeper, but every time DeGea stops a shot it is highlighted as a 'World Class save' by a fawning press. Then there is the occasional cock up for England that gets replayed a million times, and while opposition fans have not seen either DeGea or Joe for a whole game their perception is fixed, no matter what the stats say.