I am insulating a simple brick home in a third world country that needs to be able to withstand temperatures of -40 degrees. It is 45 square meters and needs to be done at a cost of $800 or less. Any ideas?

What insulation materials are locally available? Are previously used EPS boards available at a big discount? Seems like $800 might go a long way in a third world country. Straw bale walls, mud/straw walls and packed snow walls have been used by indigenous people for centuries to survive cold climates...