Actual server hardware equipment at the home is absolute nonsense.

A blanket statement like that really shows a lack understanding of what some people like to experiment with and learn. Blanket statements pretty much are always wrong.

A used R620 is a less expensive way to run x86 hypervisors and VMs than just about anything else, including used PCs of equivalent memory size. When you are buying for a hobby, you very much optimize for acquisition cost, among other things.

And if you are interested in experimenting with server management tools such as IPMI, server class RAID, SAS disks, or Xeon processors, "actual" server hardware is required.