> You pay for all bandwidth into and out of Amazon S3, except for the following:
> Data transferred from an Amazon S3 bucket to any AWS service(s) within the same AWS Region as the S3 bucket (including to a different account in the same AWS Region).
> Data transferred from an Amazon S3 bucket to any AWS service(s) within the same AWS Region as the S3 bucket (including to a different account in the same AWS Region).
https://docs.aws.amazon.com/vpc/latest/privatelink/vpce-gate...
That avoids paying NAT Gateway charges for traffic to S3 and in my testing also made a bit of a latency reduction, which came in handy once when I had a one-off data small file migration.