I found a new website that sells Japanese baseball cards that will ship to the US - AmiAmi. They sell unopened boxes of BBM (both boxes of packs and boxed sets) and Owner's League cards as well as the All Japan Baseball Foundation set (which is sold out).
I bought the new BBM Tokyo Big 6 set through them. It ran me (with shipping) about $29. I'm not quite sure how it broke down in dollars, but the set was 1995 JPY and the EMS shipping was 675 JPY for a total of 2670 JPY (shipping is half off in April) - which I think is only 170 yen more than what Deanna paid for it at Jingu. What really amazed me was how fast I got the set. I paid for the set last Friday! The post office tried to deliver it yesterday (Monday) but no one was home, so I couldn't get it until today. I don't think I've ever gotten anything from Japan that fast. (Heck, I don't think I've gotten much from eBay that fast.) Obviously your mileage may vary - I may have just gotten lucky. But I'd say AmiAmi is a welcome addition to the list of places that sell Japanese baseball cards (and I've added it to my list of links on the side of the blog).