Ya that was meeeeee!
The past few months have been perfect for a G1 Fort Max purchase, considering the AUD has been so strong. When I bought mine a couple of months ago, I had to slowly work with my seller as he visited the US post office and got quotes. My understanding is that with the new size restrictions brought in by the USPS, you can no longer ship a MIB G1 Fort Max to Australia.
The only option is to buy a loose one and have him transformed to base mode. When I got mine, I'm pretty sure only the legs were folded up. I was told that the (recently updated) maximum USPS parcel dimensions are 55x55x55cm, with Fort Max being some 52cm from head to toe in robot mode, which doesn't leave much room for bubblewrap and foam.
Again, if the seller can simply transform him into the smaller base mode you can easily get away with Priority International, which will set you back about $100AU. If the seller isn't a collector and doesn't know how to change to base mode, link her/him to
http://botchthecrab.com/archive/inst...ss_maximus.jpg
Obviously you'll want to detach the ramps and Cerebros head to free up more space inside the box as well.
Good luck with the hunt!