I don't know if I'd call myself a "hobbyist" for keyboards, but my mechanical keyboard that I am typing this on, and that I bought in 2021, cost me $35 after tax. Obviously not the cheapest keyboard in the world, but also within the reach of nearly any employed person in a rich country like the US or UK.
I posted this in a sibling comment, but it doesn't really have to be expensive regardless. I got started with the homelab stuff with a partially broken laptop. Considering that that laptop was about to go into the trash, I consider that (sort of) free to get started, but even if you don't have an old laptop lying around you can purchase a used "Craigslist Special" for basically nothing, generally less than $200, and often much much much less because you probably have a friend or coworker that has an old laptop lying around that they'd be happy if you took off their hands. Old laptops are kind of in this frustrating category of being "too good to throw away, but not good enough to use", so people will often hoard them inadvertently. Additionally, they're extremely ubiquitous; most households in the US have at least one laptop, and often at least one per person.
Even rack mount servers (used) cost very little, at least upfront. My server with 128gb of RAM and 24 cores was $150, but of course the power draw is where most of the cost for that comes from, so for those you could argue that they're a rich man's hobby.
ETA:
For those interested, the listing I ordered from a few years ago on Amazon appears to have mutated into a different item, but this one appears to be an identical product. I think for the price it's actually a really decent keyboard. I'm able to get about 120WPM on MonkeyType with it, for what it's worth.
https://www.amazon.com/Mechanical-Keyboard-Ultra-Slim-Anti-G...