The city may acquire and purchase such personal property, and acquire, purchase, and erect such public buildings as may be required for the use of the city; and may purchase, acquire, and own such real estate as may be necessary or convenient for the public good, and such personal property, public buildings, and real estate or any part thereof may be sold, leased, appropriated, and disposed of as the occasion may require as herein provided.
The City Manager, or some other person designated by him, shall be responsible for the purchase and sale of all city property, subject to such limitations and procedures as the Commission may prescribe.
Comparative prices or sealed bids shall be obtained for the purchase or sale of all materials, supplies and public improvements except
(a) 
In the employment of professional services,
(b) 
When the City Manager or Commission shall determine that no advantage to the city would result or
(c) 
When the public interest would best be served by joint purchase with, or purchase from, another unit of government.
Public improvements or the performance of any other city work by any city agency may be authorized without competitive bidding.
Purchases shall be made from the lowest competent bidder meeting specifications, unless the public interest will be better served by accepting a higher bid, sales shall be made to the bidder whose bid is most advantageous to the city.
All purchases and sales shall be evidenced by written contract or purchase order.
The city may not sell any park, cemetery or any part thereof except in accordance with restrictions placed thereon by statute.
The city may not purchase, appropriate, sell or lease any real estate or any interest therein except by the affirmative vote of a majority of the Commission members in office at the time.
All contracts and leases to which the city is a party when this charter becomes effective shall remain in full force and effect.
The authority to contract on behalf of the city is vested in the Commission and shall be exercised in accordance with the provisions of statute and this charter, provided that purchases and sales may be made by the City Manager subject to the provisions of § C-12.2.
Any contract or agreement made with form or terms other than the standard city purchase order form shall before execution be submitted to the Attorney and his opinion obtained with respect to its form and legality. A copy of all contracts or agreements requiring such opinion shall be filed in the office of the Clerk together with a copy of the opinion.
No contract shall be amended after the same has been made except upon the authority of the Commission, provided that the City Manager may amend contracts for those purchases and sales made by him under the authority of § C-12.2.
No compensation shall be paid to any contractor except in accordance with the terms of the contract.
No contract shall be made with any person, firm, or corporation in default to the city.
An individual agreement of employment shall not be deemed a contract.