Except as otherwise provided in this section, any school board may authorize the use of buses belonging to the school district for the transportation of school children residing outside such district. A fee sufficient to pay the additional costs of such transportation shall be charged each person so transported. The board shall prepare a schedule of all such fees charged, and a copy of such schedule shall be filed in the office of the superintendent of the school district. This section shall not apply to an agreement for transportation entered into pursuant to section 79-241.