Actually, USPS does include security. See the quote from their site as follows for shipments to Australia:
Note: Ordinary economy parcel post includes indemnity at no cost based on weight. For an item not over 1 pound, the indemnity is $61.28, and the indemnity increases at just less than $3.00 for each pound or fraction up to a maximum of 70 pounds, which has an indemnity of $266.59. (See 280.)
Additional insurance can also be purchased but wouldn't be necessary as the indemnity above should cover your lost cases (but postage cost is bye-bye). Post is the only real option. Even airmail is half the price of FEDEX/UPS/DHL and the like. But as I have said before, any large commercial company is not typically going to go out of their way to pop down to the local post office to mail 200 cases for only $20 bucks profit (assuming about 100% markup) unless they have a high customer focus. They either have an express driver calling daily, or would call for pick-up. Also, whilst you and I may be reasonable, I sure some psycho whose shipment is lost would continue to ring the supplier and complain without end.
NONETHELESS, I Share you deep desire to get hold of these and wish it could be easier.
I assume that the cases are made in China (although I have no basis for the assumption), so there may well be other sources but...maybe not.
If so, I just need about 50 other Aussies (Pronounced like an ageing reality TV rocker who bites heads off animals, cant act, and is even uglier than me) ..then we contact the Chinese supplier and have them imported in a shipping container...believe it or not, an entire shipping container from China only costs five times the cost of Fedexing a carton by international express. (of course I am being flippant).
LISH