S3 is a great place to keep logs data or even backups.
Monthly Basic cost:
S3 U$ 0.02 p/ GB (with Reduce Redundancy).
Glacier only U$ 0.01 p/ GB
For more detail use the AWS Calculator http://calculator.s3.amazonaws.com/index.html
I currently send about 12.5 GB daily, So here is the math:
Keep 6 months in S3 = 12.5 x 180 = 2.2 TB
Keep 24 months in Glacier = 12.5 x 720 = 9 TB
Cost S3 p/ month (6 month) = U$ 53 p/ year U$ 636
Cost Glacier (24 month) = U$ 90 p/ year U$ 2160
The way to make the files go from S3 to Glacier is thru S3 Lifecycle
You can manage the lifecycle of objects by using Lifecycle rules. Rules enable you to automatically archive the objects to the Glacier Storage Class (lower cost) and/or remove the objects after a specified time period. Rules are applied to all the objects that share the specified prefix.
You can use Lifecycle rules to manage all versions of your objects. This includes both the Current version and Previous versions.
To setup is quite easy Open
Click on the bucket, properties then Lifecycle,
Its only a 3 steps process:
Important things to remember:
Glacier takes about 3-4 hours to recover an object.
Upload has no cost, but downloading does.