How much money has your grocer spent on you? I know you’re always paying him, but what does he buy from you?
If you're going to monkey around with Milton Friedman's ideas, why not give him credit?
I explained why it is so much to China's advantage to manipulate its currency in post #16. That is how business works, particularly manufacturing, and it China benefits greatly as long as they are allowed to manipulate prices and control access to their home market.