Whenever the board deems that it will increase the salability or the price of the bonds, negotiable notes, or negotiable bond anticipation notes to obtain, prior to or after sale, a legal opinion, other than that of the Attorney General, as to the validity of the bonds, negotiable notes, or negotiable bond anticipation notes, the board may authorize the Treasurer, or the Department of Finance, or both, to obtain such a legal opinion. Payment for such legal services shall be made out of the proceeds of the sale of the bonds, negotiable notes, or negotiable bond anticipation notes.