As to what to charge, your best bet is to see what other home daycare's in your area are charging. If you go on the home page here and put in your postal code, you can see what others are charging.
but $900 for a home daycare seems about right to me. We are not big centers and most parents (but not all) will pay more for centers then a home daycare. I center doesn't close if a provider is sick and that's something parents will pay extra for.