Here is a article that will explain better than I can the difference that is going on with the China futures contracts and the ones on London and New York. No I am saying one market includes the tax as it's listed price and other does not. Why on it's own market, China has two different listed prices. Which when you subtract the vat tax you find that the prices are all comparable in China, London, and the US.
This is as the close of the market this friday.
Beijing/VAT not listed as part of the price.
628.13 Yuan/$90.13
COMEX
$90.88
Here are couple blurbs from the article.
"There is some confusion in the investment community about silver prices in China, which are different from those quoted in London or New York. This is neither unusual nor unique. The current misunderstanding is preventing investors from fully grasping important developments in the Chinese market. "
"There is a 13% Value Added Tax attached to the silver prices quoted on the Shanghai Futures Exchanges’ silver price quotes that are available and referenced by investors that actually are not applied to what appears to be the vast majority of SHFE silver trades. Thus, for an apple-to-apple comparison against London prices, one needs to look at a VAT-adjusted SHFE silver price."
https://cpmgroup.com/chinese-silver-prices/