At the age of 8, it’s not about fulfilling needs or wants, but rather teaching him how to handle money and to determine the value of it. Start with a small amount and teach him good spending habits. The sooner you start instilling good habits into kids, the easier it will be for htem in the long run.
At the age of 15, it’s slightly different as she might want things that your parents dont or can’t provide her. How much does a typical school lunch cost? Does she get it from the cafeteria (a fixed cost) or does she go out? When I was in HS, lunch was $1 a day, 25 cents or free if you qualified. If her school has that prgram then, $30-35 is reasonable. But if she has to go outside the campus to buy lunch, then that might get more expensive.
I think i started getting an allowance in high school (dont think it was earlier…cant remember)…and it actually stayed the same til i got married :pagli: