Saw the CombiBar mentioned on Marginal Revolution (link here). The purpose of the CombiBar is make payment in gold easier in a crisis because the bar is the size of a credit card and can be broken into 1g chunks.
The price of gold at the time of writing is about $1,656.65 per troy ounce. With 1 troy ounce = 31.1034768 grams, that comes to about $53.26 per chunk.
If you’re curious what the CombiBar looks like, there are some pictures (article here). I don’t know how much Valcambi (the Swiss refinery that makes the bar) charges for the card – i.e., what is the value of the workmanship involved to make the gold bar into breakable pieces.