http://www.toolbase.org/Technology-Inventory/HVAC/geothermal-heat-pumps#benefits..the ground loop is generally the most expensive component of a geothermal heat pump system and is highly dependent on local labor rates and drilling conditions. An installed ground loop stubbed out in a home can run betwee $1000 and $3000 per installed ton. Overall, one could expect to pay between $4000 and $11000 more for a turnkey 3 ton GHP system than for an air source heat pump system. Many consumers justify this initial investment with the savings they expect to realize on their heating and cooling bills over time.
this could be a solution
for many in the less solar favored parts of the country,
or for sites like my house, where solar or wind are impractical.
It may be that a new method of financing will be needed, as in
communities or utilities developing a fund to provide
low cost loans to be repaid from the savings in
energy costs.
I do have a question as to what problems could arise once you
bury the pipes, if one of the pipes springs a leak or gets
blocked.