With hardware costs going lower and lower, and rate limits enforceable to keep this for archivig, you could model a price with a suitable profit margin.
Why not buy instead one or even multiple cheap but large USB hard disc and put it into your shelve or to your friends? It gives you immediate access for free. I don't get it why one rents a service instead of staying independent.
Copies that can't be read aren't copies any more, which means regular access is a requirement, which means another recurring expense.
Different requirements can reasonably result in different solutions, but a USB hard drive on its own is simply not comparable to storage service. A redundant set of USB hard drives with a specified replacement schedule and testing procedure would be comparable -- but if you amortize all that out, we're talking about $X + Y hours per month for Z GB of storage, which compares directly to $X/GB-month if time has a dollar value.
From this perspective, I argue that storage services like S3, Glacier, B2, and Digital Ocean Spaces are priced fairly.
Flickr only allow you to buy an account for the next 2 years.