I read once**, and tend to agree with, that there is one thing no one can manipulate about any commodity where the base price is set/fixed with more or less bias on the major trade markets :
the premiums practiced by brokers and resellers "on the streets", outside the trade markets, precisely.
Those never lie whether it's increasing or decreasing demand trends.
** (will try to find the link)
"Cyril" pronounced "see real". I code stuff.
"To study and not think is a waste. To think and not study is dangerous." -- Confucius