You may purchase items on the catalogue by collecting the Merchant's Credits:

Gold - 10 Merchant Credits | Silver - 8 Merchant credits | Bronze - 6 Merchant Credits | Copper - 4 Merchant Credits

You can meet with the Showroom keepers to exchange your credits for the following:
(Please consult the Merchant's Warehouse Schedule)

Diamond - 100 Merchant Credits | Ruby - 50 Merchant Credits

The Showroom will remain open at all times for viewing;
Notice will be given in advance when items are to be rotated/replaced.