The business tax for conducting an auction of personal property in the city is twenty-five dollars for each day, or part of a day, that such auction is conducted, or two hundred fifty dollars per year. Persons selling at auction solely for charitable or benevolent purposes or under any court process or to foreclose any lien or to dispose of any property under the authority of any law shall not be required to pay the business tax. (Ord. 2063 § 2 (part), 1975).