You are charged for the IOPS and storage whether or not you use them in a given month?
Volume storage for EBS Provisioned IOPS SSD (io1) volumes is charged by the amount you
provision in GB per month, until you release the storage. With Provisioned IOPS SSD (io1) volumes, you are
also charged by the amount you provision in IOPS (input/output operations per second) multiplied by the
percentage of days you provision for the month. For example, if you provision a volume with 1000 IOPS, and
keep this volume for 15 days in a 30 day month, then in a Region that charges $0.10 per provisioned IOPSmonth, you would be charged $50 for the IOPS that you provision ($0.10 per provisioned IOPS-month * 1000
IOPS provisioned * 15 days/30). You will be charged for the IOPS provisioned on a volume even when the
volume is detached from an instance.