What if you have an uneven number of belts because you take one or put one away? It would be very instable and would tilt without the same weight front and back.
This is just a suggestion, not a knock or anything against the poster. But a solution I think could work is to rotate the hook 90 degrees and have 2 of them, one at each end. Then it would remain flat and balanced no matter where the belts are on the rack.
Not a perfect solution, you wont see or have access to the belts at the back and the mount takes up more space on the rail. But at least you aren't playing a balancing game each time you take a belt.
I think I'd hang the hook off the end, so that the belts are stored in a vertical tree (slightly sloped, so that they don't fall over each other.) But that's an entirely new redesign for something that only really matters if you care about it.
Buy a decoy belt that only gets used when you're wearing one of the real belts. The decoy belt can get a wall mounted hook so it's out of the way when no belts are being warn.
My personal solution was to not own any. But I have thought about it. Maybe a slot on both ends of the body to slide the knob of the buckle into. That would allow for two belts pretty easily.
Common? Not sure. They're available at standard shops. I have had one for 20 years that I picked up in highschool from American Eagle for $34.50. Why is that etched in my brain? I was specifically looking for one at the time.
I prefer the look (as long as it's simple) and function.
I bought a tie hanger with hooks. It lets me hang up my four belts and ~10 ties (that I’ve never worn again since the rona). I’m usually in sweat pants and hardly use my belts anymore now that I think about it. Anyway, I really like it. Think this would have more Utility and use less material with just hooks.
Try to go with something popular so you can find help when things inevitably go wrong. Expect to learn a lot when building. If you like that, awesome, do it. Otherwise you may want to consider a prebuilt prusa or bambu.
How much money do you want to put into a setup? With $1000, you an get any of the really good printers, a different size nozzle, a few little tools, and plenty of filament.