Without doing extensive research, I get the feeling that the price fluctuations are caused by changes in rates of extraction and consumption, rather than the ever increasing prices you’d expect as copper runs out entirely.

I can’t find anyone anywhere talking about copper running out. I guess claims of a “danger of depletion” were indeed unfounded.

The typical household in Mexico City buys fewer packaged goods than an American household, but it produces one third more garbage, chiefly because Mexicans buy fresh foods in bulk and throw away large portions that are unused, spoiled or stale. Those apples in Dittersdorf’s slide, protected by plastic wrap and foam, are less likely to spoil.

Hmm… So let’s see, plastic packaging is better becuase Mexican’s buy more fresh foods than they can eat before it goes bad. Isn’t the lesson here that Mexican’s shouldn’t buy more fresh foods than they will be able to eat?

Also, I don’t know where his evidence is for plastic wrapped apples lasting longer – we stopped buying them plastic wrapped from supermarkets becuase they don’t last as long as loose ones you can buy from the market

From the linked article:
Fifty years ago, for instance, tin and copper were said to be in danger of depletion, and conservationists urged mandatory recycling and rationing of these vital metals so that future generations wouldn’t be deprived of food containers and telephone wires. But today tin and copper are cheaper than ever.

Yet in actual fact, copper prices are actually at record highs

I got bored of reading after that, but I’m sure others with more perseverance than I could find more issues with this article