WX is expensive because it is a workstation card, it has nothing to do with size.
Of course I know that. What I mean is more like I am willing to pay more if that's the best of the best single slot card.
But I also wonder why this kind of card only avail as workstation card. Why a gaming single slot card cannot have 8GB VRAM, 75W TDP, 3.9 TFLOPS....?