I do believe in gold as a practical currency, but the gentleman wishes to secure his family in the event of a supply-chain breakdown; as much as I like the idea of paying for my milk and bacon with hard money, a man cannot eat coins. Physical, sustainable security is more valuable than financial security. Consider too that once established, he may trade those goods that he produces for the gold that he would otherwise be spending after the fact. I will check out those books, though, there isn't enough attention paid to books written in that transitional period.