Eliete four

Hi,i have an idea about eliete four. After battle all gym leaders we can battle a few leaders even stronger than gym leaders we faced before named ELITE FOUR. When we battle NPC trainers we earn money as a reward,unfortunately we cant battle them again.People need money all the time for important needs like for example buy pokeballs. My point is that wemaybe can battle NPC trainers and ELITE FOUR leaders many times so we can earn money every time we need. This is all of my ideas for now.Thx.