I think the issue for some people (why they may buy expensive hardware) is that their server is not “enterprise grade”, literally meaning a whole server rack with a SAN, firewall, etc. If you’re new to this hobby, please consider this unsolicited advice:

Use whatever hardware you already have or buy only what you need to achieve your goals.

Some people want to “cosplay as a sysadmin” like what Jeff Geerling sells on his tshirts. That can mean doing this stuff for fun or maybe self teaching for a job. For those folks, buying “enterprise” could possibly make sense. But I would argue that even the core concepts of that hardware can be learned on stuff you already have.

Enterprise hardware is loud, inefficient, and will likely have idiosyncrasies that making them run at home kinda suck. An old laptop is perfect as a place to host stuff or play with software.

One of the things engineers/admins have to do in a datacenter is plan for rack power efficiency. That often means planning for the capacity you are going to use, for the space you have and choosing the cheapest solution for that.

I think its considered generally more impressive with how much you can do within the constraints you have, vs having so much capacity for a cheap price. Like, how many services can you run on a Raspberry Pi? Can you create “good enough” performance for a storage area network using just gigabit? The skills you get by limiting yourself probably out perform working with “the real stuff”, even if your purpose is trying to get a job. I’d argue the same for folks who simply want to self host. Run what you got until it stops, and then try to buy for capacity again.

Your power bill, the environment, and your wallet will thank you.