At the time and place fixed in the resolution for the meeting of the board of supervisors, all sealed proposals which have been received shall, in public session, be opened, examined, and declared by the board. Of the proposals submitted which conform to all terms and conditions specified in the resolution of intention to sell or to lease and which are made by responsible bidders, the proposal which is the highest shall be finally accepted, unless a higher oral bid is accepted or the board rejects all bids. In determining which is the highest sealed proposal, the board shall not subtract therefrom the commission, if any, which the proposal provides shall be paid to a licensed real estate broker. If the highest bid provides for such commission, the board shall pay to the broker the commission specified in the resolution, as provided in Section 25527.