My family used to play four player MULE on my A400 back in the day. You WANT at least two players to collude on prices in the final round. It's the only way to get a fantastic finish. What you want to do is try to claim as much of the high and medium crystite plots as possible, and to put them all together in blocks as blocks of plots produce more than individual plots. One person needs to take one for the team/colony and make food and energy. For the very last round, buy as much extra energy and food as you can, and switch EVERYTHING to crystite, no matter whether the plot has any on it or not. Then in the last round auction, you need a player with at least one unit of the resource to sell, and one player with the most money to buy. The INSTANT sales are allowed, RUN FOR ALL YOU CAN AS LONG AS YOU CAN pushing the price up as high as possible. At the very last second, the other player will sell one unit. Do this for EVERY resource. However, crystite increases by 4 in the auctions, so you can drive its prices higher than anything else, which is why you want to focus on it the last couple of rounds. The worth of the colony is the final round auction price for every resource multiplied by how many of the resource everyone has. Driving the price as high as possible for everything in the final auction makes for insane scores for the colony... or the colony fails if pirates come and take all crystite, or the one player making food and energy gets hit in the last couple rounds. So there is some luck involved, but four players colluding can make insane colonies, and even two players can make really great colonies.