S3 vs EFS pricing consideration

To compare the costs between using S3 and EFS for your data needs, think about how you’ll be using each service. If you download 400 GB of data to EFS twice a month and keep it there for only 2 hours each time, you’ll primarily incur costs for S3 GET requests and temporary EFS storage. S3 charges per 1,000 GET requests, and while this could be minimal if you're downloading large chunks of data at once, it can add up if many small requests are made.

On the other hand, if you download the 400 GB once to EFS and then sync data twice a month, you’ll still face S3 costs for each sync operation, which could be significant if the process involves many requests. With EFS, you'd pay for continuous storage of 400 GB plus the cost of syncing data from S3.

In essence, using EFS might be more expensive over time due to higher storage costs, while frequent S3 GET requests could also lead to notable expenses. Your decision should hinge on the balance between these costs and how often and in what manner you access the data.