Except as provided in section 73-507, all proposals for sole source contracts for services in excess of fifty thousand dollars shall be preapproved by the division except in emergencies. In case of an emergency, contract approval by the state agency director or his or her designee is required. A copy of the contract and state agency justification of the emergency shall be provided to the Director of Administrative Services within three business days after contract approval. The state agency shall retain a copy of the justification with the contract in the state agency files. The Director of Administrative Services shall maintain a complete record of such sole source contracts for services.