The Priceless Statue is a black chess queen. It is found in the sixth sublevel in the Frontier Cavern and may be on the ledge near the hole to Sublevel 7 or in the water. You can use Red Pikmin and Blue Pikmin to get it or you can use the Bulbmin that can be found in the Sublevel. Make sure you defeat the Cannon Beetles and Water Dumples that may be in your way.