I think, if you can not look after your children, in this age, there are alternatives, not having more children/leaving them in a secure children's shelter.
I think it's easy to say that from a position of privilege. I'm not for a moment excusing the actions of these parents but I don't think we will ever experience, or begin to imagine, the level of poverty they live in. They have literally nothing except their bodies and their children.
And let's face it, they wouldn't be selling them if there wasn't a demand for it from sex tourists, who usually tend to be white men. I hope the documentary touched on this too. If only more efforts were made to catch those bastards 