I have collected a number of different cases over the years to store and transport my epic and 40k miniatures they range from the old old old style single layer GW cases to the old two sided GW cases, then the big GW cases. Some KM cardboard cases and then finally the cheapest and easiest available cases are the handgun case!
It sounds odd but they are cheap, readily available in north America/Canada and i just like the idea of people not really knowing what is actually inside the case. I know that in Europe and other parts of the world there are not as many gun stops or hardware stores that stock them. Then i say have a look on ebay or Amazon and see if they are cheap enough to get.