When exchanging old gold for new gold in Leofoo jewelry store, 3 grams of new gold must be purchased under 15 grams, and the depreciation cost is 18 yuan/gram; The depreciation expense of Huangbao Jewelry Store is 30 yuan/gram, but if it is below 15g, you must buy 3g of new gold, and if it is above 15g, except for the depreciation expense, the weight of the new jewelry and the weight of the old gold will be calculated according to the ratio of 1: 1.25. As a brand in Hongkong, Leofoo is very famous. Recycling diamonds or exchanging old ones for new ones has a great influence on their brand promotion. The reason is very simple, that is, selling second-hand diamonds, there is no source of diamonds (to clarify the meaning of diamonds). So only small brands do this kind of business. If it's only platinum, some stores will give you a 20% discount on the gold price that day, and then you can make up the difference by subtracting the price of the original item from the price of the new jewelry (which is heavier than the original).