The Manager shall negotiate and enter into all contracts upon behalf of the City except as otherwise provided in this Charter or by ordinance. Such contracts to be negotiated and entered into by the Manager shall be within the limits of the budget, as determined by the purpose and subject matters of the contracts. If any such contract involves the expenditure of more than $5,000.00, or the performance thereof extends beyond the budget year, or involves the expenditure of money not within the budget, such contract must be ratified by Council. The Manager shall report in writing to Council any negotiations and the terms of the contracts requiring their ratification, and the Council may in such cases alter, amend, ratify or reject any such contract. Any contract executed by the Manager on behalf of the City in violation of the terms of this section shall not be binding upon the City.