I spent a bit today drooling over renovated airstreams. Looks like one of the big names in renovations is Matthew Hoffman, of Hoffman Architecture. Check this out!
Apparently on that one he did all the work himself. Bought a used, 70's airstream for a couple thousand, gutted it, and redid everything. Total cost, doing his own labor, was around $20k. Not bad!
But then comes the question: where to put the tools? I suppose I could always buy an acre or two of desert, just outside of Phoenix, and put one of these and a small metal barn on site.