@irontoenail - Often homestays are included in exchange programs, whether they are for students or for some other reason (like people teaching overseas, or volunteering, or something like that) because they are the cheapest option and they give the person a chance to really experience life as an average person in the area.
There are also programs where people go and volunteer on local farms to help out and they get given food and board in return.
Honestly, if you can manage to get into a program like this, it is much cheaper and more fun than staying in a hotel. The only drawback is that you don't have any guarantees that your family is going to be nice. The more strenuously the company vets the people it uses, the more expensive it is going to be.
Some places are trying to change that by allowing travelers to leave reviews about their homestay hosts, but of course that has drawbacks as well.