Thanks to ameebaro’s post https://www.ozbargain.com.au/node/408767, this three-disc 4K doco is on sale. Just add another $5 dollar item, like this cable https://shop.abc.net.au/moki-portable-audio-connection-cable, and delivery will be free.

PS: Thanks to doweyy, this can be bought for $24.99 if you have Amazon Prime: https://www.amazon.com.au/Blue-Planet-II-4K-UHD/dp/B0788BMRS…