The design of these sorts of transactions in games are really insidious.

I suspect most payment providers would immediately flag single 2,500 transaction as suspect and prevent it, but breaking it up into small chunks prevents that.

That some breaking up of cost makes it hard to feel like you are actually spending money. A few 5 pound packs and suddenly you're talking about real money.

It seems like the various app stores should have some sort of preventative measures in place to stop kids from spending money (especially large sums), as it seems obvious these sorts of games are targeting them to spend money. Many even engage in dark patterns to get them to spend without realizing.