There are already different prices for gold in Zurich, London, New York, Tokyo and Hong Kong, the five main locations where gold is traded electronically. There

There are already different prices for gold in Zurich, London, New York, Tokyo and Hong Kong, the five main locations where gold is traded electronically. There are brokers who will arrange the trade for you to buy gold in one and sell in the other, at the current "loco swap" price. If that price moves further from zero than the cost of insuring and transporting gold bars with a company like Brinks, then someone does step in and complete the arbitrage. If I remember right, the prices don't typically move more than about a dollar an ounce from zero, except for Tokyo where the purity rules are different so there is an extra step involved in melting down the bars and getting them restamped. If there was some demand for holding gold in space, I'd expect roughly the same economics to apply.