The Western Digital (WD) Easystore 8TB is an external hard drive sold exclusively by Best Buy. It's highly sought after because it contains a WD Red or unlabelled WD White 8TB drive, which can be "shucked" and used in a home server.
Typically you can get 8TB for $140+tax when on sale, whereas a regular WD 8TB NAS drive costs around $260+tax.
There are more details in this reddit post about the drives and how to shuck them.
After a few hours the volume is expanded.