>>2046734If you need an expensive frame, you'll know.
They exist for people who look for something specific that the mass market doesn't offer. The frame may look the exact same to a newb, but (as an example) it has sliding dropouts for a Rohloff hub, eyelets for a front rack, a mounting plate for a kick stand, and can be opened for a belt drive.
Only very few people need such a frame, so making it in low numbers drives up the price, even though it isn't made from special materials.
And if you compare bikes from $200 to $1000, they may look alike, both have disc brakes, a front suspension and what have you, but there's a huge difference in quality.
The $1000 bike will function as you would expect, with good braking, quick shifting, no power loss in the drive train, properly sealed bearings, a geometry that was designed and tested for its purpose, and repairability.
A $200 bike can still function for casual riding, but the brakes will quickly go out of adjustment, same with the shifting, it will weigh quite a bit more, and after the first severe rain or a year at the coast, all sorts of parts will rust or seize. And the only way to repair it is usually to throw the affected part away and replace it with something better.
As a rule of thumb, you can multiply bike prices by 20 and compare them to new cars. A $200 bike is like a new $4000 car (which can't be sold in the US, due to safety regulations that just don't exist for bikes).