I'm sorry Babble, but copper price spikes have not lasted for years in the past. Look again at the spikes on these graphs.
There may be long cycles, but the highest prices seem short lived. What this suggests to me is that there are forces which work to increase supply and suppress demand quickly when prices get too high. This could be from the recycling industry where scrap copper can be brought on the maket again quite quickly. Even now there are anecdotal stories of people being electrocuted trying to steal copper power cables and such. All across the third world there are rubbish mountains with people scavenging for copper which could be recycled, there may be inventories which will be reduced etc.
It has been a shortage of smelting rather than mining capacity which has caused a supply shortfall, and there seems to be a widespead view that copper will move into surplus this year.
None of us knows what will happen to copper prices, but the past seems to suggest that there are economic forces which can reduce prices quickly.