Container homes sound like a great idea at first. America imports more than it exports so there are plenty of containers sitting around at fairly reasonable prices. Unfortunately, you need to cut holes in your new metal box for windows and doors. Then you need to build stud walls inside to hold plumbing, electrical, insulation, etc. (reducing the already limited space). Then you have to add a roof and siding to the outside so it doesn't look like a metal box. By the time you've done all this it would have been cheaper and easier to build a simple stick framed building fom scratch.
I suppose if you lived in a warm climate where no insulation was needed and you had an outdoor outhouse or something, it would make a decent cabin. Otherwise I wouldn't bother.