I think there might be a legal loophole problem over here, the same laws that govern distilling alcohol mean that stills have to be licenced, even for water. Don't know if that is the full story but it might have something to do with it?
Sounds like something is fishy. It's true that distilling water is a very energy-inefficient way to purify it. But no way should it be that expensive. It's about a buck a gallon here in TX, for distilled water, available anywhere even gas stations.

