I am intersted in a earth ship and going green but I am the working poor any suggestions?

Hi, I am currently broke as a joke and renting a trailer in missouri. But I have big plans for my future, I want to go green. I already reuse reduce and recycle, and conserve anything that I can. I am looking into buying land in about 5 years when all my kids are in school and I can get a full time job to fund a earthship or another type of self sutainig green living. What I am looking for is suggestions on where to look for land, and ways I could build my own earth ship as cheaply as possible. When I envison a eco community or green living i see a bunch of rich people.. Is it possible for poor people to live this way?
Right now I am in st charles Mo. I was hoping to stay wiht in 50 miles of here.