I don't remember seeing any (significant) numbers for Cu in the historical data, so I doubt that there are significant enough amounts of Cu to make much of a difference. Even with Cu at record highs, $4 /lb simply doesn't compare to $30 or $1400/oz. There would have to be 100 times as much Cu to compare to Au, or 5000 times the amount of gold.

Many companies who do produce primarily Cu also get small amounts of gold or silver, and because the Au/Ag is worth so much more, it only takes a small amount to make a difference. Many Cu miners, in fact, have a net cost of zero, or less, for producing their Cu because of the offsets provided by Au/Ag. But I don't think we'll get enough Cu to make much of a difference. Maybe lunch money. But don't worry- I think we might have enough gold and silver to get by.