Whether to pay your children an allowance and how much is a question that parents ask, or at least ponder. I found the following reference from Frugal Dad that might be of help.
Possibly not the best idea to pay a child for the tasks he/she is responsible for to help the family unit function but has the opportunity to earn a commission when he/she goes above and beyond the call of duty.
Riches Man in Babylon
Regardless of how or whether a child gets an allowance, I do however think that a child should learn the value and the habit of saving so that in later life this becomes much easier. In this regard I am a huge fan of the Riches Man in Babylon and particular to the Camel Trader story.