Group buy held in Korea was (as far as I Know) just once happened.
I cannot guarantee you can purchase it in same or similar price.
I also thought the price of marble was cheaper than expected, which means the group buy holder may have kind of special route, or was just special case.
Anyway, the quality of the marble is surprisingly good, and intuitively feel like the normal price of the material may be much higher than we bought.
Not sure if this matters but I have been working with tile,marble,granite for the past 14 years. I on occasion make custom shampoo shelves of stone for the customers, sometimes seat tops out of marble. Making a wrist rest would be no problem, and I can cut them with my wetsaw to accommodate, 104 size,TKL,60%, IBM 101.104,122 etc etc etc. Once when all are done I just have to round the edges which is done in 3 steps, grinding stone, then 120 grid sand paper, then 300 grid sand paper, then 500 grid sand paper and then 600 grid sand paper ( last one is done if needed me to match the stock polish of the stone)
Proof is in the pudding, let me know if anyone is interested I'll make my facebook page available for all and you can all see the pics of my work. If this ever happens, I will have to look around for the tile supliers and see what they have available, we would most likely need 20" marble tiles and like I said I will have to cut and polish and round them, we can save more than just getting them precut and prepolished, offcourse I don't want to do all of that for nothing, got to make some honey too. Shipping has to be done very carefull, marble is is fragile.