1. Jingrun pearls are imported directly and purchased from the place of origin, which saves the cost of middlemen and thus reduces the cost.

2. Jingrun Pearl won't cost too much in the production process, so it can be more flexible in price.

3. Jingrun Pearl mainly sells products through online sales and some small shops in urban areas, which can save various costs such as leasing and thus reduce the sales price.

4. Jingrun Pearl Necklace uses natural pearls instead of fake or artificial pearls, while Chow Tai Fook also uses artificial pearls or diamonds, which is relatively low in cost and will also reduce the price.

To sum up, the reason why Jingrun Pearl is cheaper than Chow Tai Fook is mainly due to the differences in purchasing methods, production costs, sales channels and raw material selection. Of course, when shopping, consumers should choose the right products according to their own needs and budgets.