Are you limiting your question to "IBM PCs?"
Because hard drives for hobbyists existed long before the IBM PC.
I built my first computer, a Heathkit H-89, from a kit. It included 4kB of RAM! I designed and built 64kB of RAM for it, which I built on perf board with wire-wrap wire.
I had a pair of ONE MEGABYTE 8" hard drives that I bought for it! They were pulls from minicomputers, and cost $800 (~1980 dollars) used, each! I spent another $400 for the controller, and a hundred or so for power supplies, cabinet, and cabling. It had a stepper motor, and was not terribly faster than a floppy when seeking, except latency and continuous read was much quicker. I think these were something like $6,000 new at the time.
I was working for Tandem Computers, and we had huge "washing machine" hard drives that held 100 megabytes on a thirteen platter removable pack. These cost upwards of $20,000, which is probably more like $100,000 in inflation-adjusted dollars.
When the industry moved to 300 megabyte removable-pack hard drives, I almost got one of the older models for a reasonable price from my employer, but I didn't have room for a washing machine, nor did I have an air-conditioned room for it, nor 220VAC service, as was required!
I recall a talk by Bill Gates in the mid-1980s, where he said that if the auto industry were like the PC industry, we'd have cars that could go 5,000 miles per hour while getting 1,000 miles to the gallon in fuel economy. Some wag loudly quipped from the audience, "Yea, and they'd crash three times a day!"
Now, people think nothing about starting a 300 megabyte download for some new app that they want to try. My, how things have changed.