The IBM 305 RAMAC of 1956 was the first computer with a hard drive — how much did one cost to lease per month, in US dollars?

Answer

3,200 US dollars

For that monthly rent (about $37,000 in today's money) you got just 5 million characters of storage — around five megabytes, not enough for a single modern smartphone photo — on a disk unit that weighed over a ton and was moved by forklift.

Source: IBM Archives / Wikipedia (IBM 305 RAMAC)