Well, actually the raw materials needed to mix
nutrient are mostly produced in China. Two third of the components and materials I use to make my
nutrients are imported from China, the rest is manufactured in Thailand.
Not sure about where General hydroponics gets most of it's material, but two chinese fertilizer producer where among the ten most successful enterprises of 2009, first was Blueberry btw. It's most likely that major US nutrient producers import at least parts of the used raw materials from China.
So what you are doing is importing back to China from the US, what has been exported earlier from there
There is a song here in Thailand, that goes about the T-shirts from numerous brand names, that are machine-sewn, at some factory by Thai workers. They get shipped to US or Europe and come back to some local mall a few month later. Then some other Thai people (or even the very same workers) buy the very same T-shirts "back" for more than ten times the price they were sold by the Thai manufacturer.
Did you know that 1kg of Calcium Nitrate (wich is a major part of any nutrient solution) is only worth 1 USD, and when sold in 50 kg packs only 35 ct. Magnesium suphate, annother major component only worth half the price of calcium nitrate? In China
all products needed should even be much cheaper.
What could possibly preventing you from buying the raw materials in China, mixing your own nutrients there and getting rich by selling it!?