The cost of winning
We calculated the cost of the three win-conditions in the figure below. Underneath the vicory point symbol, the science symbol, and the military symbol you see how much of each material/good it costs to buy all cards of the sort (respectively blue cards, green cards, and red cards).
As you can see, to win by scientific supremacy, you need a lot of refined goods. To win with military supremacy you need some raw materials and some gold. And for the civilian victory you need mostly raw materials.
At first glance the scientific victory seems disproportionately cheap. However, to win the scientific victory, you need precisely 6 different scientific tokens. Which is really hard to get by. You probably need to play double turn wonders (learn here how to play the extra turn wonders) and sacrifice a good economy for the science cards.
Refined goods
As you can see, for neither the civilian victory or the military victory you need to have much refined goods. The refined goods are necessary for most of the wonders. So if you want to win by civilian victory, you probably want some refined goods. For military victory there seems to be no need to get glass and papyrus.
Use these stats to your own advantage next time you play Duel.
Note: In this article we consider only the cost of the blue, green, and red cards. There might be Wonders or guilds that yield extra military steps, points or science tokens or cards.