The service being used here is Azure Monitor, which charges $0.10/month for each metric you monitor with alert rules: https://azure.microsoft.com/en-us/pricing/

The service being used here is Azure Monitor, which charges $0.10/month for each metric you monitor with alert rules: https://azure.microsoft.com/en-us/pricing/details/monitor/ https://azure.microsoft.com/en-us/pricing/details/monitor/ They do charge by the MB for ingesting custom metric data, but storage outbound bandwidth is one of the free "standard metrics" built into the platform. So the alert's full cost is $0.10 per month. Since they charge by the "time series," I think that means the OP could configure different alerting thresholds on storage outbound bandwidth, and they'd still only be on the hook for $0.10/month.