I have 100s of buckets and have experienced an uptick in storage costs recently. I know I can make some inventory reporting to another bucket + Athena monstrosity. But is there a sane way (Cost Explorer or 3rd party tool) that can give me some hints as to what buckets / keys are responsible? Thanks!
Have you tried S3 Storage Lens?
If you look in the Bucket tab, it shows you the trend for your biggest buckets e.g.
Storage Lens is surprisingly good alright.
Now trying to figure out if I can use “Advanced metrics and recommendations” and “Prefix aggregation” without incurring more costs than the cost problem I am trying to solve 
Pricing looks very sane FYI. $0.20 per Million objects
You can turn it off too. It’s handy for the “one a year S3 spring clean” 
This is a great feature 
