Amazon.jp does ship everywhere, but their international items use a separate warehouse, and sometimes items are only stocked in the domestic one(s) and are unavailable for international shipping.
You can get a proxy shipping address via Tenso (different service but iirc same company as Buyee) and then have stuff shipped there from Amazon.jp & consolidated and shipped to you.
I used it successfully for all the cheap and/or rare second hand books available on Japanese Amazons that Amazon will normally not ship internationaly (as its actually a miriad of small sellers listing the via Amazon and often only shipping domestically).
