I just bought 5x 2TB disks, total 10TB’s, for my Mac ! Utter madness.
Only a few years ago, it would be absurd. Nowadays, it’s just peculiar. That’s the problem.

WESTERN DIGITAL Caviar Green Power WD20EADS, 2.0TB

3.5″, 32MB cache, 7200 rpm, 8.9 ms, SATA II 3.0Gb/s, IntelliPower (5400 to 7200 rpm)