Just the other day, I saw a link about this! Here’s the detail from the article I was reading:

“If you go on landwatch.com its not hard to find a nice plot of land over 10 acres with water, trees, and arable land and for under $30,000. With these resources in mind, its not hard to imagine building a shelter built from natural materials.”

Apparently it’s a specific site to search just like you are trying to do on your own. It might be worth a look. Here’s the article where I saw it: http://www.depthcharged.us/?p=106. (It may have even been from this site, so sorry if it’s a repost – I read so much per day that I forget where I got it all! Incidentally, I am not affiliated with the referenced organization in any way, and I haven’t used their services, so caveat emptor.)