California has sufficient domestic production of formula to keep California in formula. turns out shipping things across the Rockies is a pain in the balls, and most companies prefer to not do it when they don't need to. And they're sure as hell not shipping from the west coast to the east coast..

The problem is that an east coast plant (Michigan) got shut down, so supplementing east coast supply lines is the concern. If you had to supply Cali, Australia would be a good place to look for shipping by boat, but that's not the issue, nor the method being used for shipping. Aircraft fly great circle routes, and by air it's about 2000 miles shorter to mainland Europe than Austrila (go look up flight times if you want. Non stop SFO to SYD is 15 hours. SFO to CDG is 10)

Shipping formula to the west coast, creating an excess of supply in Cali so that the excess can then be shipped all the way across the east coast would be dumb as fuck. Even if it was being shipped by by sea and land instead of air, California is hell of a lot closer to the west coast than either Australia or Europe and the east coast is a hell of a lot closer to Europe than Australia.

Also dollar conversion doesn't mean shit when dealing with commodity scale purchases. No one's going to an Australia walmart and picking formula off the shelf. They'll be paying USD at global commodity rates. Not that anyone cares about the price of the formula: The flight will cost more than the retail value of the cargo.