NCBI does not charge for the use of our software but you will be billed by the cloud provider. All costs associated with running the BLAST+ software in a cloud provider are your own responsibility. Please ensure that you delete any resources you are not using. The cloud providers all provide alerting services to avoid unexpectedly large charges, NCBI suggests that you use these services.

For AWS, please see the EC2 documentation at AWS and their pricing information. AWS also provides a Command Line Interface.