It all depends on what others charge in your area. I used to have before/after school and I charged $5 a day (regardless if the child was here for morning/afternoon or both). I might have another one this Sept and will be charging $6. I will only have the child for approx. 2 hours a day. I do not provide any food or drink to before/after school children and I don't have to do any pickups as the bus came right to my driveway. I also did not stand outside with the child. I would make sure he was dressed and had everything and out the door he went.
Like I said, it all depends on what other's charge and if you have to do pickup/drop off, supply snacks etc.