I recently gave up on home network clustering/kubernetes. I've since moved to digital ocean. I was working on data heavy apps for testing. I had several SSD zfs pools which was the driving reason, and a lot of RAM to work with.
My setup did work initially. I had a dedicated server acting as the metal lb, about 20$ a month. That was then connected through a wireguard tunnel to my home dmz network. Which backed to a dual xeon v2 work station. The latency was very good under 20ms, and really good speeds. I'm lucky to have fios in my area.
The Xeon workstation died, I then backed up to several think pads. Those were not performant either. So I got several HP t610 nodes, raspberry pi speed with sata 3. Rook took all CPU, and to boot they were running at 90c constantly. Even after re paste and with fan mods. I didn't want five little space heaters next to my desk.
After all this I ditched the home setup. I had gotten parts for a local Epyc server after my xeon's died. But sold them due the current situation.
In the end I had wanted to start a series of blogs on Kubernetes and micro service development. To help me learn and flesh out my under standing of Kubernetes.
I don't feel I wasted several months setting up Kube. I now know about under the cover stuff. Having deployed OkD, Rancher, kubespray, and kube adm. The initial wire guard set up helped cement a lot of the internal networking model. I was mildly acquainted with having worked on openvswitch and open stack before.
If you're doing local. I would really recommend a Ryzen 1600af (6c/12t zen+ 65w), either asrock rack x470, or a basic b450. Both can take ECC, and should land a little node under 500ish or so. There are also SFF PCs Lenovo ThinkCentre M93, comes to mind. But at that price 90$ a node, I'd rather move up the stack a little bit.
If you're waiting to buy local. DigitalOcean has been very well priced. If you want to learn the internals, grab a dedicated server and set up KVM, to get familiar with the internals. On the upper end you can get a new ryzen 3rd gen dedicated for 90$ a month. I look at it as a 90$ class I take once.
I'm not saying Kube is always right. But I avoided it for a long time, backing up to docker swarm. Now, I feel at a base it's not much more complicated than docker swarm, now that I've done this deep dive. Kube adm is on ease of use with docker swarm to me. Add in Metal LB, and Gitlab to help manage the cluster, you have a personal little cloud. It's also good to know for future job searches.