Although you can buy the new Samsung Galaxy Watch at places like JB HiFi, Kogan, Catch Group and others, it seems that Vodafone,Telstra and presumably Samsung's own physical stores are the places to buy the 4G LTE equipped models.
As you'd expect, Vodafone also offers the ability to buy the watch outright, or to spread the RRP of both sizes across 12, 24 or 36 months.
Vodafone is offering the rose gold 42mm model for $599, while the larger 46mm version in black is available for $649.
I'm yet to review it, beyond having some brief hands-on time at the local launch, but it is clearly Samsung's best version yet, and the most up-to-date competitor for the Apple Watch Series 4.
All the details are at Vodafone's Samsung Galaxy Watch page here.