A lot of the times if they come to like you, and more importantly if the kids like you and you can keep them out of trouble, they'll be willing to give you more maybe $50-$60, a particularly affluent family maybe even $100. If you know a family has it, (don't say that out loud, of course) you might want to try particularly hard to catch their attention with your skills. If you have friends on the "wealthy side-of-town" so to speak, try to build some small talk over time with their neighbors - trust is everything.
I am a 14 year old and I am red cross certified and have considerable experience with young cousins (as in I have babysat for them) I plan to work on weekends and fridays, so how much should I charge?