I don't get it either... same oem, same board, same is same. They are all presumably rolling off the same assembly, same MX, same pcb, same body. Different keycaps though and brand name is all that set it apart really. WASD dosen't have the usb and audio pass through, Mionix is backlit, only significant differences.
Same goes for Filco, CM, Rosewill. They are all so similar I don't get why pay 33% to 50% more for one over the other.
Xarmor, Qpad, iOne, Tessoro, Adesso, insert random re-branding, they are all equally the same build quality as well with the same faults.
Leopold, Archiss and Keycool, maybe some others, which asides from what seems like a slightly lower qc on the Keycool are pretty close as well for almost half price.
Some of it is brand awareness, some is the idea that more expensive is automatically better which is not always true.