You may qualify for volume discounts based on your current use of AWS services, outside of what you estimate in the AWS Pricing Calculator. The Calculator assumes your usage that are eligible for tiered pricing are on top of the usage of the same product last month. For example, if you used 400 TB of Amazon S3 Standard storage last month, and you use the Calculator to estimate an additional 2000 TB per month, the Calculator will assume the tier you were in last month (i.e., $0.022 per GB) applies to your entire additional usage. Your cumulative actual spend on 2400 TB per month on Amazon S3 would be less than or equal to the estimated additional cost to your current spend.