build a cobb house

After researching the Cobb buildings, I found they do not hold in the heat very well unless built against a hill, or even into the hill. Much like the Hobbit’s homes in Lord Of The Rings. I think I would like an Eagle Nest home better than a Cobb house. Eagle Nest homes are round house kits and very energy efficient, they come with many options like a computer to control lights and heat/AC, but more expensive to build.

Now that I have land to build on, this seems to be the most economical and environmentally way to go.

Someone in cyberspace, please tell me how much it would cost me to build a Cobb home, and who could do it for me?