As Burt Flickinger discussed on his weekly "Retail Roundup" on "Mornings with Maria": Costco chartering ships and Dollar Tree raising prices should help both retailers gain ground against competitors, especially Walmart, whose shelves are 20% empty because of the "supply shock," forcing it to hire 150,000 new workers. Also: Burt predicts a "train wreck under the Christmas tree" because of holiday gift shortages and weighs in on Macy's legal battle against Amazon over a Herald Square billboard lease that Amazon wants but Macy's says would cause immeasurable harm to its business if Amazon advertises on it.