All procurement transactions regardless of whether by sealed bids, quotes or by negotiation and without dollar value, shall be in a manner that provides maximum open and free competition consistent with the provisions of this ordinance and all applicable state and federal procurement practices requirements. [All purchases of supplies and contracts for contractual services, and all sales of personal property which has become obsolete and unusable shall, except as specifically provided herein, be based wherever possible on competitive bids.] Non-competitive purchases may only be made in conformance with the provisions of Indiana Code 5-22.