cost of buckets

For the first 12 months of your account you can take advantage of Free Tier. This provides you with 5GB of Standard S3 storage a month plus

• 20,000 Get Requests
• 2,000 Put Requests

Above that is subject to S3 pricing. more details . . . https://aws.amazon.com/s3/pricing/

Additionally for data that is not accessed frequently - S3 Glacier is available at a considerable discount from S3 Standard. https://docs.aws.amazon.com/whitepapers/latest/how-aws-pricing-works/amazon-s3-glacier.html

There is also a lifecycle rule that should be created in each of your buckets you upload to. AWS charges for failed uploads and they don't show up in your bucket when you look in S3. You have to look using storage lens. If you do create a rule, you should probably create it for 1 day, so you don't have to wait a long time for it to take effect. These articles usually mention 7 days. I don't understand why. Here are two articles on that.

https://aws.amazon.com/blogs/aws-cloud-financial-management/discovering-and-deleting-incomplete-multipart-uploads-to-lower-amazon-s3-costs/

https://aws.amazon.com/blogs/aws/s3-lifecycle-management-update-support-for-multipart-uploads-and-delete-markers/