- He has a permit
- He has economies of scale
- He owns the logistics and shipping
- He is the defacto controller of the port considering how scared people are of him
- He's cutting his costs of operation to a minimum by moving everything under his control since there are no middlemen siphoning of money for their own profit.
The nature of other markets like the US means the cost of production is prohibitive in most cases. This is literally the playbook on doing business from time immemorial.
Check out the billonaire cheese guy for more examples of good positioning and secretive ceos. https://www.forbes.com/sites/chloesorvino/2017/05/23/james-l...
If they start elsewhere... I guess the 18k per container that Mr. Ding gets from each sale is less than the price difference between Chinese-made and non-Chinese-made fireworks...