The Huffington Post has an interesting graphic on the costs of average child care for two children by state versus the states where the costs are more than the annual minimum wage:
I used to live in one of the states that meet the second criteria and paid child care. We lived in a small town versus metropolotian area, and the costs were much less than portrayed in the graph. It was several years ago as well, although I thought our daycare provider could've charged more than she actually did. When I first started I paid $80 a week for my oldest. When the other kids arrived, she would gave family discounts. From what I recall, I think I was paying around $180 for 4 days for 4 children, ages 2-7.