Retail jewelers, especially the prestigious Fifth Avenue stores, prefer not to buy back diamonds from customers, because the offer they would make would most likely be considered ridiculously low. The "keystone," or markup, on a diamond and its setting may range from 100 to 200 percent, depending on the policy of the store; if it bought diamonds back from customers, it would have to buy them back at wholesale prices. Most jewelers would prefer not to make a customer an offer that might be deemed insulting and also might undercut the widely held notion that diamonds go up in value. Moreover, since retailers generally receive their diamonds from wholesalers on consignment, and need not pay for them until they are sold, they would not readily risk their own cash to buy diamonds from customers. Rather than offer customers a fraction of what they paid for diamonds, retail jewelers almost invariably recommend to their clients firms that specialize in buying diamonds "retail."