[jmclnx]

Correct. Copper is relatively cheap, abundant an very easy to work with.

Gold is very easy to work with, but extremely expensive. I think if gold was as cheap and abundant as copper, it would be the go to metal due to corrosion problems other metals have.

Silver is also expensive and I think harder to work with then copper.

Aluminum, I would think it is harder to work with, but seems the article talks a lot about aluminum.

Harder to work with equates to costing more $ for manufacturing.