The problem with trying the whole "it isn't worth the cost" argument is that unlike Bundy there are many other ranchers who do pay for their cattle to graze. If Bundy doesn't have to pay than why should they? The government will never let Bundy freeload because there's more at stake than just him. If it becomes okay to take without worrying about the federal government will do it won't even just be about ranchers but also other things.
