Hand Built Off Grid Tiny House ($200) 

In video, you'll tour of both Cooper Cabin and  Allerton Abbey,

Although Cooper Cabin is not yet complete or insulated, the thermal mass of the dirt surrounding it, keeps it cool during hot days, and not too cold during the freezing Montana winter temperatures. Cooper Cabin's 900 square feet were built largely by those wanting to learn natural building, and it was build almost entirely from free/scavenged material and sustainably-managed timber from the land. It is also equipped with an efficient rocket mass heater (which warms a bench large enough to sleep on!), as well as a rocket cookstove. 

Allerton Abbey is 400 square feet. When the video was recorded, it was 90% done, and now it has been finished and looks amazing. The annualize theremal intia test is underway, and you can find out more about that--and the steps that were made to get Allerton Abbey ready--in Jennifer Richardson's thread.

Here are some current pictures of Allerton Abbey:

Here's Dirtpatch Haven's summary of their video: