I'm so tempted to use your service that I might give it a try, even though I think the price is a little too high due to what appears to be a shipping channel problem. I can get a lot of Japanese candy at my local Asian supermarket (kiwi gummis and pocky) but I'd really be interested in seeing a list of what goes in the envelopes prior to committing.
A lot of people seem to have said/thought this whenever this particular business comes up. What about a "premium" level for a higher price that allows for a better profit -- show the customer a list and allow them to pick two or three things from that list? It's a bit more hassle, but that's what the customer is paying for.
My guess is that shipping costs could be reduced substantially if the number of subscribers in a country/region gets very big: send one large package and have them shipped individually from there.