It’s an Apple-recommended accessory sold through their own store, Apple still sells 5400 RPM drives in the latest iMac,
good god, do you have anything to contribute to this thread other than being an obnoxious ignoramous? Networked storage is not the norm. We’ve already established people want to use internal drives in their machines, spinning drives are still widely in use, a $400 metal cage is extortion. Move on already!
Yes move on, the era of "I want to stuff a bunch of spinning disks into a tower" was a decade ago. Internal PCIe(NVMe) SSDs and external big and fast storage with quick connectivity is the now. If you feel you're being extorted because you want to get by on the cheap with old tech then there are plenty of 5,1s on ebay.