Sec. 89 Financial interest in contracts.
   (a)   No officer of the City shall be financially interested, directly or indirectly, in any contract, sale, job, work or service (other than official service) to be performed for the City, except as hereinafter provided in paragraph (b); nor shall he stand as, give or provide any bail, security or bond required by this Charter or the ordinances of the City; nor, personally, or as an agent, provide any bond required by law of any liquor licensee whose license is subject to approval by the Council. Any officer of the City offending against the provisions of this section shall be guilty of misconduct in office.
   (b)   A contract in which an officer or member of his family has a financial interest may be made by the City if the members of the Council having no such interest shall unanimously determine that the best interests of the City will be served by the making of such contract, and if such contract is made after comparative prices are obtained.