Before any purchase of, or contract for, supplies, materials, equipment or contractual services are made, except as otherwise provided below, the City purchasing authority shall submit to at least three (3) persons, firms or corporations dealing in and able to supply the same, or to a smaller number if there are not three (3) dealing in and able to supply the same, a request for quotation, or invitation to bid, and specifications, to give them opportunity to bid; and/or publish notice of the proposed purchase in a newspaper of general circulation within the city. He shall favor a person, firm or corporation in the city when this can be done without additional cost to the city; but he shall submit requests for quotation to those outside the city when this may be necessary to secure bids or to create competitive conditions, or when he thinks that by so doing he can make a saving for the city; and shall purchase from them when he can make a saving for the city. All bids shall be sealed and shall be opened in public at a designated time and place. He may repeatedly reject all bids, and again may submit to the same or other persons, firms or corporations the request for quotation, or invitation to bid, and/or again publish notice of the proposed purchase. He may purchase from the bidder whose bid is most advantageous to the city, considering price, quality, date of delivery and so on, and in case of a tie, may purchase from one of those tying, or may divide the purchase among those tying, always accepting the bid or bids most advantageous to the city. (1984 Code)