[kondro]

The minimum size of objects in cheaper storage types is 128KiB.

Given the article quotes $100k to run an inventory (and $100k/month in standard storage) it's likely most of your objects are smaller than 128KiB and so probably wouldn't benefit from cheaper storage options (although it's possible this is right on the cusp of the 128KiB limit and could go either way).

Honestly, if you have a $1.2m/year storage bill in S3 this would be the time to contact your account manager and try to work out what could be done to improve this. You probably shouldn't be paying list anyway if just the S3 component of your bill is $1.2m/year.