Home Slickdeals Costco “New Lower Prices” sales event for May 21th. While supplies last. Slickdeals Costco “New Lower Prices” sales event for May 21th. While supplies last. By ARCOM - 21 May 2022 66 0 SHARE Facebook Twitter Go to the deal page: Costco “New Lower Prices” sales event for May 21th. While supplies last.