All contracts in excess of a sum of money established by the Council, by ordinance or resolution, shall be subject to competitive bidding and contracts in excess of such sum shall be awarded by the Manager to the lowest and best bidder; provided that the Council may, by ordinance or resolution, establish the circumstances and types of expenditures or contracts where competitive bidding shall not be required, and further provided that competitive bidding shall not be required under this section in those instances where competitive bidding is not required under the statutory or common law applicable to general statutory plan municipalities. The Council shall establish, by ordinance or resolution, procedures to be followed by the Manager in advertising for bids and awarding contracts, provided that until the Council so acts, the Manager shall determine such matters by administrative rules.