For example, to play with Docker Swarm in a way which makes sense you need 2 or better 3 hosts, right?
What is that number for K8S?
I'd say the minimal viable configuration to test and get a good overview of pod placement would be 5 machines, 2 masters and 3 nodes.
This allows you to play with a master failure, placement of multiple pods "stretched" across the cluster, etc.