Well firstly you need to know what a price actually is. In economics and business, the price is the assigned numerical monetary value of a good, service or asset. Now you can apply rules such as supply versus demand and laws of equilibrium to determine what that monetary value actually is, but generally in most people's lives, it will be the amount written on the sticker and the amount that you're required to pay in order to get said good and or service.
Now if you apply this theory to the actual shopkeepers in China who mark uo the price of their fish, you will find that very little of what you happen to do in life will have anything to do at all with the price of fish in China. In fact, unless you happen to be either a major fishing company, a grocery chain or perhaps a maratime regulatory authority then literally everything you do in life will have nothing at all to do with the price of fish in China.
This therefore renders the question along the realms of rhetoric, in which case the best defence against a rhetorical question is usually a surreal answer; these are usually best ascribed in legal terams as these are practially untraceable.
What's That Got To Do With The Price Of Fish In China?
Well it never used to have an effect before 1997 but then the communists took over Hong Kong because the lease has expired and so the price is now dertermined by the Communist Party and part of its price policies.
Unless you happen to understand the law in relation to Chinese Price Structures then you won't understand what the answer means, so although I could tell you, there is no point really.