The first one I owned (in 1980) was a 10MB built into an Olivetti M1, but I remember seeing one at an NCC in New York (1977?) that was the first 2MB drive (for microcomputers). It was encased in a plastic shell and appeared to be made of two 8” platters.
I remember Ohio Scientific sold a 74MB hard drive on a 30” rack together with a Challenger 3 for about $11K in 1978.
HF
Oh, and my home movie library is 12TB among 3-4TB Seagate expansion drives. Cost of hardware: <$500. The space is entirely taken up (well, all but .6TB) with my home movies. ;-)
HF