Not familiar enough about GCP internal, but AWS prices are way higher than what's quoted in the article. You'll get billed for bandwidth, should you want any logs of your control plane you'll pay them at a premium so high* it will dwarf the cluster price and machine price combined. And for ~$70/month, you get the cluster API, not the EC2 compute required for worker nodes.

* Because vended logs to s3 are not supported (https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/AWS..., https://github.com/aws/containers-roadmap/issues/1141)