It depends upon your constraints. As a for-instance, I was asked this exact question a year or so ago about an on-prem object store instead of S3. The break-e

It depends upon your constraints. As a for-instance, I was asked this exact question a year or so ago about an on-prem object store instead of S3. The break-even price to go multi-region was ~15PB on paper; that included DC space, hardware, software (build vs buy was another factored discussion), and the staff to run it. That assessment was delivered with the caveat that their uptime was not going to approach S3's by any stretch of the imagination-- and their infrastructure outages weren't going to sync with "most of the internet's." It's a complex topic, and there are many hidden costs...