The big advantage of a shipping container is the ability to cheaply ship it. Once you cut into it you can't ship it anymore. It's not a great use of recycled material as it uses way too much steel for a dwelling.
I'm actually in the market for a shippable shipping container house. Similar to https://m.youtube.com/watch?v=sPgjndFqqwY . He gives the quote of $50K including high quality fittings and market price labor. I will probably build one myself then ship it to where I need it. I'm an expat and I historically move countries every year or so. If you were to build a clone of this I would buy it.
Another benefit of shippable shipping container homes is you can service customers anywhere around the globe! Not just SF.