Egress fees between CloudFront distributions?

CloudFront charges for each HTTP/HTTPS request but does not charge for origin fetches from an AWS Origin such as an S3 bucket, EC2 instance, Lambda function, or Elastic Load Balancer. In this case, a CloudFront distribution is not considered an AWS Origin therefore the requests between the two will result in double the egress fees.

If you are using an AWS service as the origin for your content, data transferred from origin to edge locations (Amazon CloudFront origin fetches) are free of charge. This applies to data transfer from all AWS regions to all global CloudFront edge locations. Data transfer out from AWS services for all non-origin fetch traffic (such as multi-CDN traffic) to CloudFront will incur their respective regional data transfer out charges.
 
This document has more information: https://aws.amazon.com/cloudfront/pricing/