Spanish release clauses always seem to be outrageously high or strangely low. 17.5m for Mata would be a banging bit of business. Arsenal need to let Fabregas go and move on. They're a big enough club that they'll always attract and develop players. They really don't need to go to such an effort to keep a player who wants to leave. From the outside looking in, Fergie and Utd handled the Ronaldo / Madrid situation much better.