First, you need $12500 or more. Then, you go to Kooroong, then Owmi, then should be a city called Nelson where you can buy gold for $500 each. Use all of your money to buy gold and you should get around 25 of them. Then go back to Kooroong and go into the gold store, just outside the port. After you go in, choose to sell all of your gold. Push down until you reach zero, then hold up. Notice that he will, eventually, stop taking your credits while holding up, because you practically dont have any. Now push down until he only buys gold for $520 and push circle. It seems like you did not gain much, but after repeating the process about 2 or 3 more times, you get about $50000. By this time you should stop, because your money would not get any higher. Do this code again when you only have about $18000 left. Good luck.