Premium items can only be bought by people with premium memberships, such as Builder's Club. However, unlike premium places, Turbo Builder's Club and Outrageous Builder's Club have their own exclusive items as well. With the more expensive memberships, such as Turbo Builder's Club and Outrageous Builder's Club, users with those memberships can purchase the premium content from the lesser memberships.
Most packages as well as a few hats and gears are premium items.
Players who have once earned a premium item but subscription for any type of Builder's Club ended will still let them keep that very premium item.