So it seems strange to me that each child would cost ~$15/hr -- the full cost of a single low-skill resource, 1:1 with children; You're not seeing the scalability of groups kick in. Unless there's some overhead per-child I don't understand, it seems clear this isn't simply supply/demand. There are many who want childcare, but there are many more who should be capable of supporting it.
There are also of course difference in popularity/quality which will contribute to a price gradient, but if you're seeing $2k/mo/child as your "basic daycare" costs, there's something up -- there's no inherent reason to the job that I can think of that would stop someone from undercutting that price point.