The board looks a little fragile. A tool like this (which is going to be used on the road) needs to be as solid as possible. For $10/unit it seems like they could afford to at least give it an epoxy surround.
In contrast, making a case is much much harder. There really aren't any good low-volume case making methods. Injection moulding is out. Machining from aluminium is an option here, but it's very expensive. There's resin casting, but that's difficult and I don't know if it's really suited to manufacture.
Honestly, making the case is 10-100 times harder than the PCB (for such a simple one like this anyway).
tinkercad.com to create an stl file, and shapeways.com to print it out.
(simple) PCB design and production is super quick and easy though, you're absolutely right.
That said, I think $10 is a good price for something like this. I, personally, would look for a corporate/industrial application that would justify a price 10x that.
i've been hassled for a cubieboard. (a single board ARM computer). They seem to hate exposed PCBs. You'd think they would have seen quite a few...