The best possible way to handle this would be that you can only buy these things IF you've cleared the appropriate floor. For instance I've never been below floor 100, I cannot buy the music rolls allotted to floor 150 and floor 200, they just don't show up. So if the Firecrest and Glass Pumpkin are the same then only folks who have cleared that deep will be able to buy them. Whether they make it possible to sell it on the MB.

(If it already works this way ignore me, like I said I've never been down that deep.)