Should the penny be abolished?

Each coin is justified only as long as there is something more or less frequently bought for the price of that nominal. If cheapest thing in your average grocery store cost a quarter, everything less is simply redundant. Price of producing that penny is somewhat irrelevant as long as reprocessing that penny is not worth it. Gold had that problem (You can smelt it anywhere and it's somewhat hard to spoil it unless you are really determined to do that). All in all, it's not used only once.