Well I think the point is that it is small enough that you can place the purifier on the other end of the pipe (in the home) and so what contaminates the water

Well I think the point is that it is small enough that you can place the purifier on the other end of the pipe (in the home) and so what contaminates the water on its way there isn't as much a problem. But then again like you said, even at $1000 it's more than an individual living there will afford. Maybe they will institute some sort of program where people can donate purifiers to villages?