There was a lot of useful information in the above post, thank you!
I am in a similar boat to you in that I chose to to travel and live on the road for numerous years instead of working towards a career. Thus I am working low paid jobs and aiming to save up enough cash to buy land and build a home/food forest, I also am thinking that a majority earthbag build, infused with many other techniques will be my best option.
Having lived in many Latin america countries, I will end up in that part of the world because not only do I love it, but also its tropical,land is cheap and building regulations are way more relaxed and even non existing in some parts.
I briefly looked at cheap options in Europe and Portugal seemed like the best bet for me in terms of climate and value. Here is an example. http://www.pureportugal.co.uk/listman/listings/l0749.html
They say "Ideal for a low impact home, like a yurt, tent, caravan or mobile home" maybe this is because the land only has permission for temporary structures.