Kelly already is paid handsomely thanks to his latest extension, well above what is common for first time head coaches in the NFL. He will not double his salary to become one of the league's highest paid coaches if he lands an NFL job.
If Kelly becomes a major success at Notre Dame, he will be compensated among the highest paid coaches in college football; and colleges have begun to match the NFL which means he will be compensated among the highest paid coaches in football period.
I can understand wanting to compete at the highest level. The best way to get that opportunity is to be great at the current job. Because Kelly isn't close to that kind of accomplishment at Notre Dame, his best move is to shut up (and shut Trace Armstrong up) and do his job better.