The crystal jewelry in Donghai, Jiangsu is basically a wholesale from Keitang, Guangdong. Why do those business customers who buy goods in Donghai do not go directly to Katang, Guangdong to buy the first -hand

The crystal jewelery of Jiangsu Donghai basically has a wholesale from Katang, Guangdong. Why don't those businessmen who buy goods in the East China Sea directly go to Kotang, Guangdong to buy first -hand goods?