I heard all of these tips 10000 times already!! but how- where, should I do it?? rich boys, give money using weak Pokemon, gentlemen, etc! its all the same. WHERE?? thats the real question, I think, if u heard this before, then, yes, it is.
Outside the safari zone in the fence maze area, there’s a guy who gives you 10,000 for every win after you beat the elite four. With an Amulet Coin, Happy Hour Smeargle, and Money O-Power lvl 3 rewards 120k If you keep playing and rematching him for a hour (every 10/15 minutes IG) you should be able to get 500k+ :)
His name is Walter and you know you're challenging the right guy when he says "I've traveled the world's four corners with my Pokemon.”