My old group’s first hard drive was a 10 mB Winchester for a DEC system - total cost for drive and controller came out to $100 per mB. A 750 gB drive I bought last week for a desktop system came to $0.00027 per mB.
My summer job in 1988 in digital imaging had the old DEC platters the size of a chair. About the time I showed up they started failing frequently and leery eyes started looking at me. Turned out that the air conditioner was not being kept on during the weekends per mgmt and the heads would crash in the hotter/thinner air. They ended up paying $5K each for a ‘modern style’ hard drive (about 65MB IIRC).
If I'm thinking of the same drive it took a healthy man to carry one of those up three flights of stairs (and most women wouldn't consider it, except for one female DEC Tech who was in better shape than most of the men).