The board of education issuing any warrants hereunder may pay the cost of printing the warrants, the cost of advertising the sale, the attorneys’ fees for preparing proceedings, the attorneys’ fees for furnishing an opinion as to legality acceptable to the purchaser and other expenses incidental to the issue of the warrants, but only the actual cost thereof shall be paid and all such payments shall be made to those actually rendering such services and not to the purchaser of the warrants, in a lump sum or otherwise; provided, that the board of education may employ any bank or banks and person or persons to assist in making arrangements relating to the issue of refunding warrants hereunder and the sale or exchange thereof and may pay them for such services subject to the approval of the State Superintendent of Education. This section shall not authorize the payment of a commission or other compensation for procuring a purchaser of capital outlay warrants issued hereunder.