They're already very cheap, almost free when you buy used. I got one for $50 that makes pretty good prints. For $300 you can buy an Elegoo Centauri Carbon that is a really high end consumer printer. Don't forget that we're talking about CNC machine tools with precision movements here. An entry level manual milling machine from Precision Matthews in Taiwan will cost you $250 shipping alone. Even good linear rails by themselves are more than $300 on ebay. A lot of innovation has been happening in the 3D printer space to make all these machine components cheaper which has also benefited other applications like hobbyist milling.

Nowadays, we are so used to all the injection molded plastic crap, and also so much poorer, that we can't understand why precisely manufactured products made from solid metal or wood are so expensive.

> Like solid machines sub-$100.

You can get 3D printers from BestBuy(!) for $200 retail. At that point, the cost of the filament is going to quickly exceed the cost of the machine.

At the $200 price point, your Bill of Materials is roughly $65 (about 1/3 of the retail cost). I challenge you to buy the raw materials of a 3D printer for under $100 let alone $65.

I think its the Ender that goes as low as $170 or so, which isn't terrible.