The ST-506 was an early personal computer hard disk, introduced in 1980 with a capacity of 5 megabytes and a price of $1500.
While several sources confirm the price, I haven't been able to find whether it was wholesale or retail. The difference matters; a wholesale price of $1500 typically translated to a retail price of about $4500.
The one piece of information I have been able to find is https://www.gizbot.com/computer/features/things-that-you-should-know-about-hard-drives-044120.html "A 5 MB hard disk drive from Apple cost $3,500 in 1981." That would be consistent with $1500 being the wholesale price in 1980 (and some decrease in the course of a year). Is that correct?