Geothermal Heating and Air Conditioning

I have contacted several heating contractors about installing a ground source heat pump in my home. I live in a 125 year old house on a large lot which could easily accommodate a closed loop, horizontal, slinky coil but no contractor has called me back. How much do these systems cost? They are free if you live in your house long enough and/or sell your home and recoup the initial cost. Aren't there any contractors out there who will contact me about installing one of these?
Watch this funny video about the features and benefits of the system.