even just x10 cheaper would put it at double the price of LCD and that already has uses
Giant E-ink screens are expensive because they're made by fusing together 4 smaller e-ink screens (4 of 10.3" or 13.3" screens IIRC), but the process is expensively done by hand because there's simply not enough demand to warrant automating the process. There's just no money in giant 1Hz monitors.