(1) Crushed rock or gravel not directly used or needed by the county in the construction, repair, or maintenance of its roads may be sold by the board of county commissioners at not less than actual cost of production to only a:
(a) person, firm, or corporation desiring to use it upon any public street or highway in the county; or
(b) landowner for personal use in an area within 5 miles of the opencut operation where the materials were mined.
(2) The proceeds of any sale must be paid into the county road fund.