An estimate of the cost of the improvements of the proposed subdivision shall be prepared by the subdivider, stamped and signed by a registered civil engineer licensed by the state, and shall accompany the improvement plans each time they are submitted. Cost estimates shall include a separate item for contingencies in the amount of ten percent of the estimated actual cost and a separate item for construction management, engineering and inspection in the amount of seven percent of the estimated actual cost. Upon consideration of the estimate submitted by the subdivider, the city engineer shall determine the estimated cost for the improvements of the proposed subdivision. (Ord. No. 1500, § 3 (part).)