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You have purchased SQLBackupAndFTP Professional version 10 on 05/19/2017 without "Free 1 year updates" option which allows you to get free updates to new versions for 1 year. Without this option only 30 days free updates are included.
Your license never expires and you can use the version you’ve purchased forever.
$64 is the price for the upgrade from your current version to SQLBackupAndFTP Professional version 11 without the one-year subscription.