If they sell Llorente, then every talented player they have at some point will ask to be sold, that way they would actually lose more money since in 99% of the cases players get sold for way less than their buy-out clause. Not to mention all the headaches they save that come with negotiations, instead they keep it simple, you want the player - you pay for his buy-out clause.
And they don't really need money since they don't buy anyone that isn't Basque.
I for one admire them.
I guess we'll have to disagree since I see it from the point of view of the player. If I'm a talented guy, though unfortunately come from the Basque region and made my name there, I'll want to win trophies. You can't do that there, or at least very, very rarely will that happen. Besides, who doesn't want to play for a Barca, Madrid, Juve, Bayern, etc.?
However, because of this attitude, it's impossible to have something beneficial for both parties, transfer fee for the club and a move to prove myself for me. No, instead they go "Fuck you, and everyone like you. I own you bitch, and you are staying until I say you do". I mean, you can admire that all you want...but yeah, I'd rather side with the position that benefits both parties.