3D printers and laser cutters are significantly cheaper now. Also those and CNC machines, people can use them for business like you send them the file and they ship you the item. Laser cutters people use for custom engraving, they just buy a bunch of blank keychains, coasters, etc off alibaba and make them on demand. You can find tons of these stores on etsy (people will just steal the models for popular characters and print them out on demand for a profit), here's a more expensive one. Or like my family, print out warhammer 40k models instead of buying them because it's literally cheaper.
Also these they might not have bought them new, like our university will rarely get rid of equipment to free up storage and because it's so specialized and so few people know how to get access, you can get a really good price. We had two rooms of printers that we had to get rid of because students kept breaking them and it was too much of a pain to keep them running. We also bought new milling equipment to upgrade the shop and got rid of the old stuff which was working fine.
My dad fixed up a Chinese laser cutter to save money (it was like 1k by the end of it), it sat in the basement for a while there. Personally, I assume YT is not their only job. I've worked with people that have sunk way more than 10k into their hobbies, the car people in particular are sometimes unbelievable and that I don't get. Drone and boat people too. The small planes are kind of cool. At least with these tools, you can actually make money off them.