Using harvested rainwater can make a major dent in the water bill. And when using insulation features, electricity usage is reduced to a large extent.
Hot water insulation reduces geyser/heat-pump costs. And room insulation maintains the room temperature. A radiant heating and cooling system throughout the floor of the home makes temperature control cheap.
All these savings result in a reduction in living costs and eventually, a great return on investment. Within about ten years or less, the extra amount that we paid for the green home is retrieved with these savings. We also gain a profit when we sell such a home.
To add to this, green homes have a low impact on the environment, making them even more valuable.