on E. Grand Ave is where I have purchased gold coins in the past, but they do charge a bit of a surcharge.
As far as apocalyptic gold /spending money investments, I would think the most practical form would be some of the large coins, plus a lot of the smaller ones (such as 1/4 oz Maple Leafs). The coin form IMO “guarantees the gold content” to people you are trading with, versus just unmarked lumps of gold. For smaller purchase get a boatload of JFK silver dimes, IMO.