A factor must obey instructions of the factor’s principal to the same extent as any other employee, notwithstanding any advances the factor may have made to the principal upon the property consigned to the factor, except that if the principal forbids the factor to sell at the market price, the factor nevertheless may sell for the factor’s reimbursement after giving to the factor’s principal reasonable notice of the factor’s intention to do so and of the time and place of sale, and proceeding in all respects as a pledgee.