This is bit better disk as compare to X16 and cheaper as well. here is the data sheet for comparison. https://www.seagate.com/files/www-content/datasheets/pdfs/ex...
Locally in Australia it is still more than $800.
There are two different versions of this drive diffrence is not much. Usally X16 is cheaper but this price is better than X16 drive. X16 been cheper before Here https://www.ozbargain.com.au/node/657510.
There is quite a bit discussion there as well that might answer some of your questions
Exos x16 has a write speed of 440 IOPS vs X18 550 IOPS
Exos x16 draws up to 5.0 watts of power to function vs X18 5.3 Watts
Exos x16 has a slightly lower noise production than the Exos x18.
Digital storage capacity 16 TB
Hard disk interface Serial ATA
Connectivity technology SATA
Special feature Seagate Secure
Hard disk form factor 3.5 Inches
Hard disk size 16 TB
Form factor 3.5 inches
Item weight 1.48 Pounds
Hard disk description Mechanical Hard Disk