For those of you who are interested in having books shipped internationally, I have finally figured out what I'm doing (mostly). I will send the books the cheapest way possible. Sometimes, if you order a lot of manga, the cheapest way is through Flat Rate Priority. Most of the time, though, if you're only ordering a few (5 or 6 manga), then the cheapest way appears to be First Class International. Regardless, I thank those of you who live overseas and have made purchases from me for your patience while I stumble through this.
Also, I maintain my list on very carefully, so whatever is on that list in my shop are the manga that is still on my shelves, waiting for a home. Once I have a solid confirmation of a purchase, I remove the books that are to be shipped, so my list is always up-to-date with my current inventory. :D