For the time and work you are describing, $25-$50/hr is not as outrageous as you think - regardless of your age. If you want to be a photographer, you have to be able to see yourself as being worth what a photographer is paid. If you have confidence in your ability and can deliver, then don't let your age undermine your ability to do the job for what the job is worth.
Besides, once you set the expectation level low, it's much more difficult to raise it later.
For comparative purposes, look at it this way - approx. 8 hrs of multi-location shooting formals, culminating in a dance party (most likely) in low/poor light. That sounds a lot like a wedding to me. Would you shoot a wedding for $300???
