For us as well it's not a question of $ but of enough. ExH worked for water companies in Europe, Hong Kong, and Australia so was more cognizant of what goes into it than most.
"How much is enough?" is one of the questions that brought me to and has kept me coming to this site. I tend to be extravagant in some ways - airline miles used, sugar consumed, secondhand clothes and furniture purchased and donated - and skimp in others.
After 15 years in Asia, the fact that most westerners shower in *drinking water* still blows my mind. So much unnecessary processing of resources. To make my water potable I boil it, let it cool, then filter through a Brita and chill.