I just bought an antique pinball machine. I'm going to invite my friends over and tell them it's pay-for-play.
Why would you charge them?
All my friends are short on cash and I'm not about to let them play for free. I'm doing this for their own good.
It is rude to charge your poor friends to play games at your place. You won't have friends for long if you take all their money and they feel cheated.
I think it would push my friendships to the next level.
You got that right, it'll push your friendships to the next level -- down. If you know your friends are short on cash, I don't get why you'd want to charge them. Friends are supposed to help friends, not try to squeeze the last penny out them.