EBS volumes are the most common way to store files on AWS. They offer scalable and reliable persistent storage. They can also get expensive if not managed properly.

If you follow a couple of basic rules, you can ensure your monthly AWS storage bills will remain at a reasonable level:
– make sure you update your volumes to the latest type of the same family (e.g. upgrade to the latest GP3 as it’s cheaper and more efficient)
– don’t over-allocate the volume size and IOPS level, it is easier to extend EBS volumes than it is to shrink them
– maintain CloudWatch alarms and review metrics regularly to ensure you use the correct type of EBS (some metrics are available only after installing the CloudWatch agent on your EC2)
– make sure you don’t keep any EBS volumes in the ‘Available’ state, those are not used by any resources. You can create a much cheaper snapshot and delete the volume
– use Trusted Advisor, and its Cost Optimization -> Underutilized EBS feature to get a quick glimpse as volumes that are reported as underutilized

The storage cost tends to take a large portion of the AWS bill. Remember to review your resources regularly to ensure you can get the most out of them.