I've just placed my order online. Someone told me I could click and collect from one of the Lego stores. But I wasn't given the option at check out so I just chose delivery. It turns out you have to order on the Lego Certified Store website (which is separate from Lego.com) in order to do click and collect:

https://lego.bricksmegastore.com/pro...-optimus-prime

Lego.com allows 2 per household while the Certified Store website allows 1 per household.

Stores that you can click and collect from:
Canberra
Charlestown Square
Highpoint Shopping Centre
Karrinyup
Melbourne Central
Robina Town Centre
Townsville
Westfield Chermside
Westfield Doncaster