Here are two common questions in regards to Oracle pricing and licensing on AWS:
1. How can they determine the pricing for an instance launched from an Oracle AMI e.g. https://aws.amazon.com/amis/oracle-database-11g-release-2-11-2-0-1-enterprise-edition-64-bit?
The bottom line: The pricing are the standard EC2, data out traffic, and storage + cost of Oracle licenses (or no cost of Oracle licenses if they have their own)
2. How do they manage BYOL or using unused licenses in practical terms? (afaik they have to BYOL for Oracle on EC2)
The bottom line : It is up to the customer to make sure they are not violating Oracle licensing policies.