Much of the green building is more expensive because the demand is not as huge. So they don't mass produce like some other componies. It's kind of like HD or Lowes against a local hardware store. The small guy has to pay bills too with a higher price. When there will be more competition for green I believe the price will drop quite a bit.
As far as water, obviously it's more than taking a leak, it goes to the pond then it goes to tap!!!

There is alot of treatment for water and much of it can't be filtered when things like drano and other harsh chemicals are introduced, not to mention harsh chemicals from the raods and any power plants the sends chemicals in the air. It is then dumped into the streams and build of polluted water begins. Also, most of the water we use and drink comes from aquifers very deep in the ground. All the water is filtered though rockbeds which can take up to 100 years to penetrate(that' why it tastes soooo good). The problem there is we are using the water way faster than it can repleninsh itself and are tapping out the aquifers. I know it sounds funny but we are actually running out of usable fresh water for human needs. The more we pollute the water the harder and harder it is to clean and drink. I know some of you would like to bash me on this but this is the truth and we all need to think about all the actions we take because it affects everyone.