Anyone knowledgeable on AWS billing? My parents have a Synology NAS in their basement, and for the last couple years I've used Synology's Glacier Backup app to back it up to AWS Glacier, the storage option for people who want storage but don't necessarily need timely access to their data. Until maybe earlier this year, it reliably cost about $2/month to back up maybe several hundred gigabytes.

Over the last several months (maybe since Jan-Mar? I'm not sure) the price has slowly but steadily increased. I just got a bill for $12, for example. How can I figure out why it's doing this? I thought part of the issue (if not the whole thing) is that it seems my sister's laptop is backing up to her share on the NAS and there is a ton of data on there. I deleted all the previous backup versions, so those should have dropped out when it backed up last night but the cost doesn't seem to have changed when I look at the billing amounts and I"m just not sure where to look.

Any help?
THanks!