In order to do some POCs over Mesos, Kubernetes, DC/OS and more, I would like to build a small cluster of 3-5 nodes. I started to build a cluster via AWS, but it becomes expansive fastly. So, I was wondering if there is a good way to build such a cluster without spending too much money on it.
There is a blog where the author gives a good explanation and open source code for a cheap 3 nodes HA production cluster. It's in Digitalocean but could be replicated in any similar host provider. It's too long to post everything here so check this link
You can use DC/OS Vagrant to spin up a local DC/OS cluster. You do need a pretty burly machine for it to work since you're basically running a full DC/OS cluster, and if you plan on testing out any data services or big workloads there, you'll need an even bigger machine. (check on the requirements)
That depends on whether you want to use the Cloud or not. Alternatives that come to mind could be:
In all of these cases, you could follow guides to build your cluster from scratch like https://github.com/kelseyhightower/kubernetes-the-hard-way (note that this is meant for GCE but most of it is applicable to other systems)