The kids probably won't even be grateful for it anyway, and it'll just set the bar that much higher. The parents will have to live up to those expectations from then on because blowing a fortune on concert tickets will be the new standard.
What's the worst that's going to happen if you tell your brat you can't afford to sink five figures on a concert ticket? They tell you they hate you? They should have started doing that around the age of three or four. There's nothing wrong with setting boundaries, even if you can afford to spend that much money on a concert.
If it's an attempt to rekindle your kid's interest in you as they get older, most kids don't really hang out with their parents and if you have to buy your child's attention and affection, it's probably not going to be worth it. Like don't parents bitch about how they can't stand being around their toddlers because the brats cling to them 24/7? You think they'd enjoy their kids wanting nothing to do with them as they get older.
The Moos of these kids probably don't have any friends their own age anymore, so they have to try to befriend their kids.