For example, I’m sure the average joe doesn’t know just how expensive calligraphy pens can be, or how deep the rabbit hole goes on video game speedruns.
Playing music has basically no skill ceiling.
Keyboards are generally known about, but the ergo part of it is a rabbit hole within the rabbit hole. Some people literally design, 3D print, wire up, solder and program one-off keyboards because they don’t like the ones made by other people.
It’s infectious too. I REALLY want to get good with one! and don’t get me started on the absolute craziest style: chorded keyboards! Insane!
Gymnastics. The skill part is obvious but monetarily its more than i expected. I thought it would be like going to a regular gym but its usually much more expensive to use the gyms and thats if you can find a time slot where adult males can train.
Probably more well known but with the whole ‘live edge’ fad from a couple years ago now, some people don’t realize you can spend upwards of 20-30k on a single piece of some types of raw lumber.
I feel like woodworking is one of those traditional “this hobby is expensive” things, but I was shocked by just how hard it is to do some things (like hollow out a bowl-shaped divot in a piece of wood) without the proper tools. And the proper tool is sometimes a single hook knife that’s $89 dollars.
You can get 8 foot of pine from any hardware store for $10, but if you want to do anything other than cross cut that pine to different lengths, you’re going to need to drop some cash.
Of course, the skill ceiling for woodworking is enormous.
Model trains. Sure, you can have a lot of fun with a 100 dollar toy train, but those brass engines are very shiny and very expensive.