I only have a couple reference points around this scale:
My dad's company had a system set up with a searchable index of a bunch of legal testimony. It was a Compaq Deskpro 386 running Unix with an attached 1GB disk. The 1GB disk set up was as big as the machine itself.
A few years later, I worked with a Cyber mainframe equipped with around 30GB of total attached disk storage. The disk array literally filled a room.
256MB disk on an 80's PC would have definitely been quite a bit.