@Tom Gunnison - That's cool that you have a local company doing this. Can you give the name of the company by any chance? We might be able to find out more about this building niche by contacting them or looking over their website.
@Chris Winterhalter - I can definitely see how this type of reuse would be good for disaster areas. As far as disaster areas go the New 3d House Printers coming online are pretty cool for that sort of thing as well.
http://www.smh.com.au/digital-life/digital-life-news/ten-houses-in-24-hours-from-chinese-companys-3d-printer-20140504-zr4mm.html
I am similarly impressed with the finished housing. The designs are pretty cool and are much more interesting and aesthetically pleasing than I would have guessed possible. I agree multifamily investing is a far less intensive strategy and I hope to be in your position sooner rather than later =).
I agree the savings would be dubious though and the issue of marketability for resale makes it a tough decision. I'm sure the unique recycled design will appeal to some but it definitely reduces the buyer pool. I'm not sure the market would even be large enough to support a niche builder of this sort in most parts of the country.