While the idea of buying commodities might fit your criteria (though I would disagree with that notion), Cash4Gold is not a great model: http://consumerist.com/

While the idea of buying commodities might fit your criteria (though I would disagree with that notion), Cash4Gold is not a great model: http://consumerist.com/5144296/10-confessions-of-a-cash4gold-employee http://consumerist.com/5144296/10-confessions-of-a-cash4gold... Ebay, despite its problems with scammers, is a good example: a store that sells almost everything, with no inventory costs.