I'm going to offer a different perspective. If a high school kid (perhaps even junior high) wants to do an extracurricular, either through school or outside, and the family absolutely canNOT afford it, the kid is old enough to understand that if they want to do something, they need to come up with the fees.
A kid can babysit, be a mother's helper, do chores/yardwork (rake leaves, shovel snow, cut grass, weed, pick produce, etc.) for neighbors elderly and not. There are also paper routes (some communities have weekly newspapers that don't require a daily committment like a daily paper).
Friends of older kids report that the teenagers seem to have a more difficult time getting part-time jobs (it seems to me that adults are taking these jobs due to the tough economy), but a kid can still do the yard work/babysitting route. Problem is, many of the kids do NOT want to do the work. A couple who are empty nesters have a house with a not-huge yard. Their work schedules don't allow them as much time as they used to have for yard work. There are teenagers in their neighborhood. They've offered the grass cutting job to several of the teenagers - name your own price. The kids didn't want it - "too much work."