That's useful market information, but note that in the "How much did it cost?" section he points out that the BOM is ~$400 not including labor, tools, or shipping. Going from extremely low-volume to moderately low-volume might reduce material cost slightly, but I'd still expect him to have to charge at least $400 just to break even.
More generally, I've never seen a low-volume split wireless keyboard for less than $200 and the closest in design I can think of would be https://lowprokb.ca/products/corne-ish-zen which had a base price of $320 before pricing in keyswitches or keycaps.
It's totally reasonable that this is your price point and everyone is different -- some people would never pay more than a hundred bucks for a keyboard, whereas I have a couple keyboards that are more expensive than the computers they're connected to.
I am also a keyboard snob, and have far more expensive keyboards. Mass manufacturing drastically lowers costs, and a price point goal is super useful for group buys, which I have run before. It is useful data.
I'm also talking about PCB + case only. The case is the biggest cost driver here, a simple FRT plate case would make my kit price reasonable with a healthy margin
