Some alternative construction techniques (most of these will let you build a house - doing the work yourself in an unzoned county - for $10-15 per square foot, and even less for farm buildings.  This is far from a comprehensive list:

1) Cordwood masonry:  You cut cordwood into 1-2' sections, and stack and mortar it like stone.  You could build a two story house with 18 cords of wood ($100-150 per cord), plus foundation and roof. This is my least favorite, because it's the least heat efficient (though much better than a stick-built structure) and I think it's ugly.

2) Straw bale:  stack straw bales like bricks, using steel rebar to stick them together, and stuccoing the outside.  There are 100 year old barns in Kansas build of straw bales, and it's the prettiest.

3) Cob:  Basically building with chunks of dirt-clay, and plastering the outside - this is a really old technique, and holds up well.

4) Wood/plastic underground - this is actually my preferred method, but it really depends on being somewhere where zoning people won't bother you.  It's basically wood construction sealed with plastic sheeting, underground or partially underground - wood is stronger than concrete, and if you seal it with plastic it's ideal - if you dig down four or five feet, and then throw the leftover dirt on top, you have a structure that barely requires heating, doesn't need cooling, and is safe from the weather.  It's also far and away the cheapest method, and works just as well for barns and animal shelters as for people. 

If you had access to logs, you could basically build a log cabin and bury it using this method - it would work with round logs, but would be even better if you squared them off.  Log cabins are pretty easy, except that when you get the wall high enough, it's hard to lift the logs - doing it partially underground means that you only have to lift them a few feet.  I had thought of doing cordwood masonry this way, but I read recently that it doesn't work very well because the log ends must be exposed in order to breathe (which is also why I think it's ugly, but a lot of people like it).

One of the few drawbacks to this technique is that you can't use propane for cooking, because propane is heavier than air and using it underground is inviting trouble.

No matter which method you use, the key is not to think that you need a giant house - it's better to build a smaller house (which also requires less heating), plus outbuildings for storage.