i dont think you got what i was saying. what if you NEED something form someone and you have nothing to trade them for what you need? they simply dont want anything you have? what then? just because you stock piled a bunch of food doens't mean you wont have a need. what about medicine? what about an herb to cure a weird disease you never expected to get? etc.
dont count solely on food as a bargaining chip. that too is speculative investing. the wise investor spreads out his investments, thus limiting his risk.