Why are external drives cheaper?

Why are the external drives cheaper thna the bare OEM drives of the same type?

For instance a WD black 1TB 2.5" is aboit $80.
A WD Black Game 10 5tb sells for about $130-150

???

Hi @Ezio,

The price of devices will be depend on the capacity and performance.

The actual drive in external drives are lower quality than internal type drives . Manufacturers justify this practice by saying external drives.