Infrequent-Access Storage has 30 Days minimum charge per Item
- Go to https://s3.console.aws.amazon.com and get the file listing for one of your buckets.
- Note that each file in the bucket has a storage class. The choice of storage class is under your control and affects costs.
Standard
is the most expensive, so some people use infrequent access
which has a lower monthly fee (~50% discount) per GB stored according to the table of prices. BUT, Infrequent also has a $0.01/GB retrieval charge, so only saves on total costs for files stored at least one month and retrieved less than once per month. Also, there can be a lifecycle policy on your bucket that changes the storage class of files over time, which can affect when the 30-day minimum storage period kicks in.
In the fine print, infrequent access
has a minimum charge of 30 days for each item stored.
Source: https://aws.amazon.com/s3/pricing/
First footnote, marked †
† S3 Standard-Infrequent Access and S3 One Zone-Infrequent Access
storage have a minimum billable object size of 128KB. Smaller objects
may be stored but will be charged for 128KB of storage. S3
Standard-Infrequent Access and S3 One Zone-Infrequent Access Storage
are charged for a minimum storage duration of 30 days. Objects that
are deleted, overwritten, or transitioned to a different storage class
before 30 days will incur the normal usage charge plus a pro-rated
request charge for the remainder of the 30 day minimum. Objects stored
30 days or longer will not incur a 30-day minimum request charge
What's expensive about Amazon S3, and Google Cloud Storage as well, are the network charges if data is sent out onto the public internet instead of kept in that company's cloud. The network charge for retrieval one time can easily exceed the storage charge for 3-4 months. $0.09/GB (Oct. 2018) for AWS S3, $0.12/GB for Google Cloud Storage, lowest usage tier.
Digital Ocean has an S3 compatible storage layer called "Spaces" that might be worth checking out. Some bugs have been reported, and it might be throttled in some ways, but the overall pricing looks interesting and it might be "good enough" for some uses.