If people are serious about using gold as a unit of exchange at this point, it’d have to be done on a weight basis, not a face value, e.g., I’m going to pay you 10 ounces of gold to remodel my kitchen. Assigning a face value tied to the Fed’s funny money utterly defeats the purpose.
You give the clerk a silver bar worth $1000 for tax bill of $875. What do you get for change?