Checked out our Bunnings yesterday on the way home. All they had were the big ones (900x500???) for around the $200, and some REALLY HUGE ones that were on a pallet outside ($270-ish?).
They were labelled "Cargo Cases", but they're still not showing up on the Bunnings website. The guy I spoke to on the service desk didn't really know anything about them, other than the smaller ones were over there, and the bigger ones were outside. Which is a shame - I thought that a couple of the same size as Mandrake's above would be good as food boxes in the camper.
Ahh well - I'll have a look for them each time we're in there - they might just get random stock sent to them.
Cheers,
Matto