Parents optimizing for the long-term benefit of their children over current comforts for themselves isn't exactly unheard of. It is apparent that this is a family which believes that it is important for their children to receive an education from that school.

Maybe they know the kids are technically/scientifically inclined so they are sending them to a school with a better science program than the local schools. Maybe they are religious and believe that their children need a religious education. Whatever it is, it's because how their children are educated is more important to them than owning a home.