Hello Vinay, I recently set it up for cluster mode and 7-Mode filers in my NAS environment. As Netapp Harvest is available now without any additional license so you dont need to buy a specific licenses to use it. All other tools like Graphite and Grafana are open source solutions with optional support model.
For example, Grafana have some support plans for those who want to consider them.
https://grafana.net/support/plans
Hope this answers your question.
Cheers!
Deepak