18TB Western Digital Red Pro NAS Hard Drive 2 for $600

Cache Size - 512 MB
Disk Speed (RPM) - 7200rpm
Interface - SATA
Transfer Rate - up to 272MB/s
Compatibility - Designed with CMR technology for medium or large-sized businesses in RAID-optimized NAS systems with up to 24 bays. Perfect for archiving, sharing and handling high-intensity workloads