I still use docker-compose in development even with k8s in production. I recommend you checkout kdm (recently released in k8s 1.4) which will help you setup a cluster on a single node in less than 5 minutes.
As for time investment, k8s is kind of an all-in-one solution. It will take care of rolling updates, container restarts, monitoring so you won't have to roll your own solution. It will definitely improve your workflow. Kubernetes also takes advantage of declarative configuration files so it's super easy to bring up a new cluster somewhere else by just applying your config files again.
Also, Kubernetes is a good investment because it's not tied completely to Docker. Whatever container technology reigns supreme in the future should work with k8s no matter what.
As for time investment, k8s is kind of an all-in-one solution. It will take care of rolling updates, container restarts, monitoring so you won't have to roll your own solution. It will definitely improve your workflow. Kubernetes also takes advantage of declarative configuration files so it's super easy to bring up a new cluster somewhere else by just applying your config files again.
Also, Kubernetes is a good investment because it's not tied completely to Docker. Whatever container technology reigns supreme in the future should work with k8s no matter what.