From what I know about it, it was a member exclusive, but there was no limit on production. So I'm guessing they made exceptions for the regular overseas retailers like BBTS and if you had 8 friends living close by, you could get as many as you liked. I don't think there's much of a requirement to join the club, so long as you pay and live in Japan/HK.
The only thing I can see preventing it from falling in price is the snowtrooper. First box set with an Imperial army builder like that and a cool one too. Me, I think series 8 is going to have a snowtrooper and they're delaying the announcement to ensure they sell as many of these as they can.