Which, according to the article runs less than $10000 (180 TB * 1000 GB/TB * .048 $/GB = $8640 )
270 TB is using 6 TB drives.
Backblaze uses 4 TB drives because of the increased costs and failure rates of the 6 TB drives.
https://www.backblaze.com/blog/wp-content/uploads/2015/03/bl...
(270 TB * 1000 GB/TB * .051 $/GB = $13770 )
My original estimate of $20,000 was just a rough estimate that added some padding for overhead and accessories.
Which, according to the article runs less than $10000 (180 TB * 1000 GB/TB * .048 $/GB = $8640 )