Starting October 31, 2022, regardless of where a self-hosted runner is deployed, network egress incurred from restoring a Workspace or Cache to a self-hosted runner will be billable.
Previously, self-hosted runners deployed in AWS us-east-1 were exempt from all Network Egress billing.
One way to optimize usage is to use a local caching strategy with your self-hosted runner instead of using the built-in Caching/Workspace functionality.
Details on Network egress: Persisting Data Overview - CircleCI
Impacted customers will be emailed twice between now and October 31, 2022 with details around their historical usage to get a sense for how this change may impact their monthly credit usage.