This week I've read about several Vandwellers who've recently purchased cheap land for parking (for at least part of the year).
You may have read about Nemo's land purchase here:
Nemo purchased his land through an Ebay auction:
I've been meaning to start a list of sources for buying land for the vanstead:
If you have other sources (especially if you have first hand information), please leave a comment. I'll be adding to this list as I find new sources.