This is a pretty good deal for those looking for a great NAS drive with high capacity.
These retail in Australia around $650 so there is a decent saving there. Even with current eBay 10% coupon, cheapest is $597.60 from Computer Alliance.
Lowest price according to CamelCamelCamel was $344 + shipping around a month ago, this is still a very good price!
Doesn't look like there is a limit to how many you can purchase, example pricing of multiple drives including delivery to Victoria:
1 drive - USD $372.11 (~$513.42)
2 drives - USD $739.23 (~$1,019.96)
3 drives - USD $1,216.99 (~$1,679.15)
4 drives - USD $1,620.83 (~$2,236.35)
The 16TB externals are maybe cheaper if you wanted two 8TB drives - usually $499 US plus postage. I didn't realise reds could be 7200rpm though so these may be a different drive?
https://www.amazon.com/16TB-Desktop-External-Drive-WDBLWE016…