More like $1M at current prices at this scale / level of performance.

If you go with HDD arrays probably $50k

Boy pricing is pretty nuts these days. I have half a petabyte in Seagate enterprise drives myself and I didn’t pay anything close to that to acquire it. Such a pity about the flash storage. 2 years ago we built 200 TiB or something of flash using Samsung PM1633 or something and it was a fraction of the cost per gigabyte that $1m would imply.