OK. Putting a little bit more thoughts into this now that you mention it. I think there should be certain (perhaps most) housework that they do that shouldn’t earn them money. They need to learn responsibility as well rather than making everything a financial trade. But they would be rewarded extra for noticing things that we need help on and getting that fixed. Maybe fix the sprinkler, I can pay them 5x to 10x the material costs. I want them to discover problems and then fix them.
In fact, that’s something wrong with our society. I have numerous kids knocking my door asking for donation or sell me some junk, but why no one has knocked my door and told me my sprinkler is broken and offering fixing it. I would gladly pay 5x for the material cost too for their parents’ effort of raising the kids right.