It happens to all sorts of players, Bale has a proper agent and he was still stuck in a bad situation with Madrid. It's more about context than anything else, some situations will be complicated no matter what, Tottenham is one of them, they are not a selling club, in the sense that they do not have a strategy of developing or maintaining their current position based on sells. And they are not at the top of the food chain either which means that their players eventually look up and want to move, you just need to look at the moves for all their top players in the last decade it has always been difficult from Berbatov to now Kane.