@Mahadev, Rakesh [HAEA] Welcome to Microsoft Q&A Forum, Thank you fo rposting your query here!
The charges for enabling SFTP (SSH File Transfer Protocol) on an Azure storage account are calculated based on the time the service is enabled, not just when data transfer occurs. The rate of $0.30 per hour is applied as soon as you enable SFTP for your storage account and continues to accrue every hour it remains enabled, regardless of data transfer activity.
To manage costs, you can disable SFTP when it's not in use, which will stop the hourly charges. When you're ready to use SFTP again, you can re-enable it, and the charges will resume. It's important to note that disabling and re-enabling SFTP will not affect your configurations or local users; they will remain intact and functional after the service is re-enable
If you need detailed understanding, I would recommend to please contact Azure Billing and Subscription team would be the best to provide more insight and guidance on this scenario: https://azure.microsoft.com/en-us/support/options/ based on your region and requirement. it's free, and it's the best choice for you.
Transaction, storage, and networking prices for the underlying storage account apply. All SFTP transactions get converted to Read, Write or Other transactions on your storage accounts. This includes all SFTP commands and API calls. To learn more, see Understand the full billing model for Azure Blob Storage.
Please let us know if you have any further queries. I’m happy to assist you further.
Please do not forget to "Accept the answer” and “up-vote” wherever the information provided helps you, this can be beneficial to other community members.