After I investigated the merchants, I found a fantastic fact. The shipping cost of a small item like the size of a hand, the average amount is 0.5US$, from China to worldwide. It even is getting cheaper!
Not believe it? Let me tell you another miracle. From Yiwu to all over China(except Tibet, Xinjiang, and Inner Mongolia,) the cost of Small-item shipping is 0.8RMB, which about 0.11US$! (https://finance.sina.com.cn/chanjing/cyxw/2020-03-20/doc-iimxyqwa1839701.shtml)
People tell me in person, and the news is reported.
But HOW? How they make shipping cost 0.11 USD domestic and 0.5USD worldwide?