Well in all fairness TEX aluminum TKL cases from mechanical keyboards are $150 with shipping included/free shipping so people may expect a bit more value in a surrogate case for another board as it is not a custom.. But, I still would expect to pay more for a larger case, from a smaller production run, and on top of that shipping from across seas.
Though, I would think if people are comparing prices they would be looking at the GMK uniqey keyboards and comparing the price of a configurable full keyboard with keycaps, aluminum case, and bluetooth to this one and that is where you have to convince people one way or another.. And this is where aesthetics will come in too, as both boards are very different looking from each other (conventional vs what I have heard some call 'the banana').