Well, I collect coins for my hobby not just for investment so anything for my collection is frivolous.
The most recent waste of money was 10 American Open Currency Standard (AOCS) 1AV copper rounds. I am getting nine different issues so it is an instant collection!
Paying around US$30 by the time I add postage from USA so probably not the cheapest way to buy copper. However,when SHTF I can use them for bartering, apparently as they all have a dollar value.
Last copper round I bought was the Ron Paul Liberty Dollar which managed to escape the FBI raid, US$13, cheap at the time as I bought it from the UK and there wasn't much action on the auction, the same thing was selling in USA for around 3x that price so I still got a bargain