"Channing, can you make one item that can not be duplicated?"
"No, but—"
"Uh-huh. Now we go back to barter and exchange."
"Golly!"
"Furthermore, chum, what are you going to barter with? A ton of pure gold is the same value as a ton of pure silver. That is, aside from their relative technical values. A ton of pure radium won't bother us at all, and if we want Uranium Two-thirty-five, we make it by the ton also. Oh brother, you've really screwed the works this time."
"Now what?"
"You and your crew start looking for something that is absolutely un-reproducible. It should be a light, metalloid substance of readily identifiable nature, and it should be ductile and workable. We need a coin-metal, Channing, that cannot be counterfeited!"
"Yum. That's one for the book. Meanwhile, we'll retrench on Venus Equilateral and get set for a long, long drought."
"Check. I'm about to do likewise with Interplanet Transport. You don't know anybody who'd like to buy the major holdings in a spaceline, do you? It's on the market, cheap. In fine condition, too, in spite of the depredations of Hellion Murdoch."
"Might swap you a communications company for your spaceline, Keg."