K8s allows scale up and down. Having 2 different environments for prod and staging shouldn’t cause much extra costs of each can scale down on low usage. There’s a benefit in doing so: If your staging services accidentally require a huge amount of resources due to some of your own bugs, i.e. memory usage blowing up, you may easily pull down production for that due resource/monthly costs boundaries. The little extra money to run 2 clusters may be worth the money!