As of 2015, air conditioner fan motors vary greatly in cost from $90 to $500, according to Grainger. Prices vary by brand, materials, design and capability.
An air conditioner fan motor can be specific to a certain air conditioner, so use discretion when selecting the one that is right for your machine. Grainger and Home Depot both provide complete product descriptions that include specifications for the air conditioner fan motor or condenser fan motor.
Size, weight, rotations per minute, amplitude and motor type can be specific to a certain machine. The manufacturer should be consulted before purchasing an air conditioner fan motor to make sure it is the right fit.