API to monitor old unaccessed files?

Cold storage is cheaper than object storage. I’m trying to figure out if it would be viable to check every x days for large files not accessed or like 6 months and move them to cold storage.

I don’t know if it would be a good idea to save money.

Also, is there people here using object storage instead of disk/block storage?
My provider charge per gb for block and is cheaper per gb for object but charge extra bandwidth to retrieve files (totally normal).

What’s your thoughts ?