one consideration is that they'd have to buy large quantities to get a bulk price, stock it, and store it. if they don't buy enough, they get a poorer price.
as well, i'm going to take a lucky guess that the prices don't go up linearly. that is: .50 thick is not twice as much as .25 thick; it's probably more.
as it's heavier, you have less pieces, more shipping costs, more storage for less items. prices go up.
and let's face it, not everyone is going to be buying 1/2 inch thick slab knives at any cost. same for 1/4 inch.
now, if they did a special edition sprint run, and they sold out, vigorously, it might bode well for the future, but they're not going to order a ton of weird stock on a whim.
not saying it won't happen, it's just unlikely
and it would be expensive...