You could also PM hiho, I know he had some copper ingots some time ago - not sure if he still has them but if you're interested it's worth asking him
PS: Copper, zinc, etc. are not precious metals. This thread would best be called "Bars of industrial metals". How about stacking pig iron?
Thank you to all that have taken the time to respond. It seems that I will just for educational purposes get a whole bunch of fun 1gram sized bars, but not expect them to fetch anything afterwards.
I was thinking about copper sheet. Not terribly tough to work with - make some useful stuff we wouldn't think of until the shtf. spirit still, solar water heating etc. In a post plastic/oil/america world the increase would have to be relative to the usefulness, and copper friggn rules. Look how much it was used before our current plastic generation. Particularly if you live somewhere isolated from copper production. Sheets = easy to stack. if copper did go "to the moon" you could mint "coins" less of minting, more regular weighted squares cut and stamped with weight would have to be tradeable. Remember there <1oz gold/person on earth, even if there was 10x as much silver (many argue there is less) copper comes in as the next metal to be traditionally used in coins.