The problem is that if we sell Suarez, we might struggle to attract a similar calibre of player here. Top players want to play with top players, and he's just about the only one we have left. Not only would it signal that we're a selling club, it would leave us with the most uninspiring group of players we've had in decades.
In the real world, we should count ourselves lucky that Suarez came here in the first place, and do our very best to hold onto him. But if we really do plan to sell him, we'd better make damn sure we have some top quality replacements lined up beforehand. After all, we've wasted much larger sums than we'd get for Suarez before now, and I'd hate to see our biggest asset replaced by Henderson and Downing mkII.