(1) A public entity shall, in preparing the cost estimate of goods, prepare it subject to Rule 9 and the specifications of the concerned goods.
(2) In preparing the cost estimate of goods pursuant to sub- rule (1), the following matters shall be taken into account:
(a) The actual cost incurred in the procurement of the same nature made in the current or previous years by the concerned public entity or other public entity of the district where such a public entity is located,
(b) The rate prevailing at the local market,
(c) The rate prevailing at another market and estimated cost of transportation of goods to the place of their delivery,
(d) The rate issued by the Chamber of Industry and Commerce.