In any situation where it might be relevant, how are you going to sell your gold?
For example, if you bought one of those bars right now, how would you then sell that bar again right now?
And, if things really are completely collapsing, nobody wants gold. They'll want something much more immediately useful--food, clothing, ammunition, etc.
I did look at this to see if it was cheaper than any jewelrymaking gold I could buy, but the prices are bang on identical per ounce.