Investigate Spot Instance Bidding Rules to automatically bid for Spot Instances
This is a follow up on the suggestion introduced by https://gitlab.com/gitlab-org/gitlab-ce/issues/13666#note_95716519.
The article in the referenced comment (https://www.twosixlabs.com/bidding-for-builds/) also suggests Meltano project could also benefit enormously from using spot instances, as it's a perfect use-case for that.
Based on the conversation with @likewhatevs I think it makes sense to have some kind of integration implemented on the runner, considering especially the auto-scaling context. To autoscale using spot instances, you may need to have a bidding mechanism implemented inside it.