Everyone has been wondering this for months actually.
To start with, the actual value is 2600 yen which is currently $23.70 U.S.
Now, you can go with HMV Japan and if you order three at a time, your final price delivered by FedEx will be roughly $90 which is $30 each. That's how I got mine, 3 a month. Sure it's a little high for shipping.. but compare it to the prices charged by CD Universe or Amazon before shipping.. $36 and up.
You can get cheaper shipping from CD Japan but I don't have an exact total for you since I didn't go that route.
I liked HMV because most of the time they shipped fast and the delivery ends up being basically 2nd day by FedEx., plus they always have plenty in stock.. CD Japan has trouble keeping stuff in stock and takes a little longer before they ship too.