OP indicated elsewhere here that they’re trying to cover some of the costs with side projects, but €720 anually is a big bill to foot for less affluent parents.
I don’t want to get into whether the ability to afford these things for your children makes you more/less of a good parent…
But if you can afford it, you absolutely should support their passions. The only reason I’m a high salaried software engineer is because my parents generously bought me a computer, allowed me to attend classes (programming in BASIC), etc.
Eh, power bill is the best one for an increase to appear on, way more wiggle room before anything important is shut off.
Plus if we're talking about being poor it has two important benefits 1) excellent hours occupied to dollar spent ratio 2) engrossing hobbies typically mean they aren't out there rattling around stirring up trouble (which can get expensive in a hurry)