Advice needed about pricing, simple or complex

[AcornsFalling]

I would suspect the rates vary more by age in larger centres because they have strict rules about ratios of child care provider to # of children and are talking large numbers of children.
I care for 2 children in addition to my own 2 and I charge $50 per day, for a 9 hour care day. Some parents use the whole time and some don't, but even if they don't, they still pay for the full day. I don't do drop in or half days. The parents sign a contract for what days their child will attend and pay for that space. I also charge the same rate for all ages.