In the interim, can I suggest the following for your customers grouped in a single country (I'm using the example of the USA since that's what I know best):
- Find a friend in the states
- Set the boxes up so they're ready to ship from your friend's city to the subscribers' destination (you can do this with USPS online printable mailers in the states)
- Ship them all in one big box to your friend
- Have your friend open the big box and dump the contents directly in the outgoing mail
I think this would save dramatically on postage.