How does a GON case like that differ to the WKL.kr HHKB case? (Which costs ~$40)
The middle layer is Polycarb, that can be only be CNC machined. Top and bottom are anodised alu, also CNC machined. This is why the price is higher than a winkeyless.kr one. It's just something else, even if from the outside they look the same they are not.
Yeah, the kind of machining that goes into it is what raises the price, and also the thicker plate that's used for the switches which requires more machining to set notches for the retaining tabs, then the countersunk screw-mounting positions and the aluminum feet mounting holes.
Poly is apparently hard to machine as well. I've taken a dremel to PC to make inserts for my Duck Lightpad, though.
And that turned out nice! Nah, I know it can't be compared. It was also hell to do by hand, haha.
You can certainly see the quality in GON's machine work, but for it to rival the price of heavy aluminum cases is still kind of crazy to me.