Wish I could give gold to boost this, because while I understand everyone else's emotional responses, realistically there's next to nothing a kid can do when their parents are like this other than hope they can find a mandatory reporting trustworthy adult (generally: teacher, school counselors), and that some sort of good comes from that. Maybe they can find a friend to crash with to get out earlier, but that's a hard ask.

Doing the same as the parents/brother goes against OP's morals. It sounds like retaliation in any form against the brother would be somewhat futile, as they're "parents precious spoiled baby" and if found would likely result in even worse treatment. Hiding the controllers is mild, but that's $60 a pop, if they wind up hiding those every few days to every week, someone's going to catch on. No one has a place to store 50+ controllers, and unless their parents are rich rich, I doubt they'll be okay with constantly pissing away that money every week, even if it is for "their little angel."

Maybe the school would come up with a small fund raiser to help them go where they were saving for, or maybe it'd start a chain to get an actual loving family member custody. Or maybe it'd do nothing. But it's leaps and bounds better than purposely poking the bear, and hoping it doesn't lash out worse than it's already been doing.