Well...maybe and maybe not. I had a friend who was after me to go geothermal as I was saying it was time to replace our old, high efficiency system. It would take 4, 50 foot wells based on our energy usage, BUT even with out the wells the payback was nearly 50 years or about twice the lifetime of the system. A second contractor came up with pretty much the same figures. When asked how much our gas and electric ran, the one wouldn't believe it until he wet over a whole years worth of bills. In the end the conclusion was that geothermal, although "slightly cheaper to run (it'd save us around $140 a year, the overall cost would be far more than conventional.
This is a very efficient home for insulation, windows, and water heating.