Okay that makes sense. Nathan Brown (coach, not the player that fakes injury) was saying the other week that there's no such thing as a bargain buy anymore. Brown signed Jesse Ramien (overrated anyway) and he played 2 games for the Knights before his father was in at the club saying they were ripping him off and demanding a release for a promised upgrade back at the Sharks. But even if he did go to another club for less money what's to stop them from upgrading it eventually and making up the shortfall anyway?
All you can do is make sure that the player doesn't make anymore money on paper. Ie if they have two years to go with clux at 500k then the salary cap hit club y has to take is the same. Now if they can make it up with third party deals it's impossible to police unless the nrl gets their hands on a players tax return which would make it harder. Good luck getting the players to agree to that though,