I don't know how it is in Brazil but in Europe and the US offices frequently go out of business that have dozens if not hundreds tiny desktop computers in their bankruptcy auctions. They've got i5 cpu's 4-8gb of ram and 128gb SSD's and go for (much) less than a hundred bucks. Stack 3 of them and you have a kubernetes cluster that you could carry in one hand and I think outperforms the 7 raspberry Pi 3's.

Servethehome has a series of articles about the machines, though they're focusing on the slightly higher end ones.

I think it’s lease companies replacing paid off business PCs. They rent boxes to offices on multi year contracts, collect and recycle them when the term is up.

If you have a PC, then just run it on VM(s) on that. That's what AWS is giving you anyway.

Here's an example: https://kubernetes.io/blog/2019/03/28/running-kubernetes-loc...

Thanks for reading! It's probably worth implementing it in the cloud using the free credits if hardware is prohibitively expensive, at least for the purposes of learning.

If you do intend to self-host some services in the longer term, the cost of running it on the cloud will catch up with the hardware cost in no time at all.

Or you could also checkout lowendbox.com (not affiliated with them). They provide really cheap vps servers.