Is AS Billed?

AS is free, but you will be billed for pay-per-use instances it automatically creates. For pricing details, see Billing. EIPs used by the instances are also billed. When the capacity of an AS group is reduced, the automatically created instances will be removed from the AS group and deleted. After they are deleted, they no longer generate any fees. Instances manually added, however, are only removed from the AS group. They are not deleted, so they are still be billed. If you do not need these instances, unsubscribe from them on the ECS console.

For example, if two instances are created when an AS group scales out, but then an hour later, the AS group scales back in, the two instances are removed from the AS group and deleted, and you will be billed for that one hour of use.