it wouldnt be that crazy in the real world, before modern medicine your baby had a really good chance of dying anyway. when everyones popping out 10 kids and half of them die the way you think about children is very different. also just the fact that your entire life will change if your kid is selected, although these stories always makes everyone look attractive and healthy so you dont really get the feeling that peasants even need money, it just looks like greed.