Miss. Code § 31-7-18
In addition to the method of purchasing authorized in this chapter, said governing authorities are hereby authorized to accept the lowest bid received from a motor vehicle dealer domiciled within the county of the governing authority for the purchase of any motor vehicle having a gross vehicle weight rating of less than twenty-six thousand (26,000) pounds that shall not exceed a sum equal to three percent (3%) greater than the price or cost which the dealer pays the manufacturer, as evidenced by the factory invoice for the motor vehicle. In the event said county does not have an authorized motor vehicle dealer, said board or governing authority may, in like manner, receive bids from motor vehicle dealers in any adjoining county.
No purchase of a motor vehicle under the provisions of this section shall be valid unless the purchase is made according to statutory bidding and licensing requirements. Provided, however, that the governing authorities may choose to purchase a motor vehicle from the authorized state contract dealer without having to advertise and receive bids therefor.
No purchase shall be made in excess of the approved state contract price by any of the aforementioned governing authorities when such authorities are situated wholly or in part in the county wherein the authorized state contract dealer for a particular item is domiciled.
Miss. Code § 31-7-18