I don't like Lebron, but Lebron is 100% correct. The CBA has put a maximum on what a player's contract can be. Unfortunately for Lebron, he is such an amazing player that his worth as a player is waaaayyy over that maximum that the league has set.
It isn't about making sure that you're getting paid millions of dollars. It's about the principle - that in fact - the league is in fact underpaying him, and thus he feels like he is being stolen from/taken advantage of... which he is.
Of course I understand that it was bargained for by the players association, but nevertheless, it doesn't take away from the facts that I have pointed out above, and that Lebron is 100% correct. He's not being cocky, he's being realistic.