What to Buy and Build
Deciding which units to produce is important to any commander. Buy new units and licenses to complement your existing forces and to take advantage of your foes' vulnerabilities.
Consider overall unit effectiveness (which takes into account speed, carrying capacity, and combat strength). But you should always be budget-conscious. Sometimes the best unit is not the best deal! If you can get five good units for the price of one great one . . . maybe "good" is good enough. Watch the economy to get the most value from your Ultranium. The Unit Cost History link in Com-Net can be very useful.
Why buy what you can steal? When you capture a world, can you use its licenses to produce what you want?
Why pay for a license if you can trade? If you have a friendly neighbor who is making something you want, perhaps you can work a deal. (Few units are worth transporting across interstellar distances, but there are exceptions.)
And watch Com-Net headlines for information on new units and upgrades!
Scarce Resources
The balance between Cost and Complexity will shift over time, even in a game that doesn't use the Economy rules. Early in the game, populations are low and Complexity is usually the limiting factor. Later in the game, Cost often becomes more important. This is because even though every world produces new Population and new Ultranium every turn, the Ultranium is used up, while the Population remains, and populations grow steadily unless destroyed in battle.
This means that a unit which is uneconomical in the early game may be affordable in the late game, because its high Complexity is no longer an issue.
Upgrades tend to have a higher complexity to cost ratio than the items they upgrade. So if you are running low on Ultranium while producing Zenrin War Monks, then perhaps you should consider buying ZinCho Mystic Breath to upgrade the effectiveness of some of your Monks, rather than leaving your Population idle while they wait for more Ultranium.
