The US Post Office issued a set of four postage stamps to commemorate the exposition, with designs depicting a profile of Vasco Núñez de Balboa (1¢), the Pedro Miguel Locks of the Panama Canal (2¢), the Golden Gate (5¢), and the discovery of San Francisco Bay (10¢). The stamps were first put on sale in 1913, to promote the coming event, and perforated 12, and then reissued in 1914 and 1915, perforated 10. Their prices today range widely; the 2¢ of 1913 is available for under a dollar in used condition, while an unused 10¢ of the scarcer orange-yellow variety in 1915 can be worth up to a thousand United States dollars.