If requested by a county legislative authority, an agency of the state managing state-owned lands, other than state trust lands, shall consider leasing a requested portion of these lands that are not used for any significant purpose and if not otherwise prohibited, to the county to be used as county fairgrounds. If it is determined that such a lease shall be made, the agency in setting lease charges shall consider the fair market return for leasing the land, the public benefit for leasing the land to the county for county fair purposes at a level below the fair market return, and other appropriate factors.