Distinguish Redshift Spectrum from Redshift Costs

Redshift billing is independent of any cost that may incur due to querying S3 data using Redshift spectrum. When customer queries S3 data using Redshift Spectrum it involves- 1) spinning up compute environment which are part of the Spectrum managed fleet and is complete transparent to customers. These fleet of servers are taken from hot pool of servers managed and maintained by the Redshift service. Customers do not pay for these servers as they are baked into Redshift pricing- both on demand as well as RI pricing. 2) Scanning and retrieving the requested data from s3.

The only cost that customers need to pay for quering S3 data via Redshift SPectrum is the s3 scanning cost. And the cost is $5 per TB data data scanned. AWS Billing has added the feature to drill down API operations by Service. Yes customers can retrieve the Spectrum cost from the Cost Explorer by filtering out Service = Redshift and group by API Operations and look for the line item "DataScannedInTB ($)". This will provide the cost incurred by Redshift Spectrum. On the contrary if customers filter by S3 and hoping to find the DataScannedInTB there to extrapolate Spectrum cost, it will be incorrect. Hope this helps.

You can check the https://aws.amazon.com/redshift/pricing/ page for pricing associated with Redshift Spectrum.