A company has established a pilot factory on a process it has developed. A heat regulator is needed in this factory. The company has determined that after a good bargain, it can buy the heat regulator for 30 million TL and use this device in different places on the production line. It is estimated that the scrap value of the device at the end of 8 years will be 35 million TL. If the firm believes that 15% is a good yield rate, what will be the annual gain from the purchase of the heat exchanger?