Thing is, the Minimig has it's own formfactor, you'd have to build a case from scratch. And you raise a point about the sandwhich case, dust is never a good thing for electronics.
I too like the looks, it's a clean design. I won't be ordering one soon though, too expensive for me and I already have an option on an original Amiga 3000 which will be mine in just under two weeks time.