Expenditures shall be made according to procedures established by ordinance of the City Council for all budgeted items exceeding fifteen thousand dollars ($15,000.00). All contracts or purchases involving more than fifteen thousand dollars ($15,000.00) shall be let to the lowest and best bid by a responsible bidder after there has been an opportunity for competitive bidding in accordance with the requirements of V.T.C.A., Local Government Code Chapter 252 and any present or future amendments relating thereto. Provided, however, the Council shall have the right to reject any and all bids. Provided, further, nothing herein shall apply to contracts for personal or for professional services nor to work done by the city and paid for by the day as such work progresses nor to the purchase of real estate, nor to any other expenditure otherwise excepted from the competitive bidding requirements of state law. Emergency purchases are authorized under circumstances and in accordance with procedures set forth under V.T.C.A., Local Government Code Chapter 252 and any present or future amendments relating thereto. Preference to local bidders in the purchasing of real property or personal property not affixed to real property is authorized under circumstances and in accordance with procedures set forth under V.T.C.A., Local Government Code § 271.905 and any present or future amendments thereto.