In September 1990 I was purchasing HP's MONSTER 1 Gig HDD for $3,600 each. They were 5.25 format, double height(4" high) and weighed 20 lbs.

By January 1991 they were down to $1,600.

Now I am looking at an 80 Gig 2.5" format HDD for my Archos MP3 player. 2.5" format, 9mm height, less than 10 oz., $150!