Along the lines of ramping costs, someone posted at the TWC this article awhile back on the best time to upgrade units.

If i decide to attack with 20 light inf in my army it will cost me approximately 1550 food and wood for the units themselves and 740 food 520 wood for the upgrade if i build before i upgrade.. total cost will be 2290 food and 1970 wood. Now if I upgrade and then build it will cost me 2620 food and 2250 wood for the units and 140 food and 120 wood for the upgrades. so 2740 food and 2370 wood. total these up to make it 1 number and you are looking at 4260 total resources if you wait on upgrades and 4870 if you upgrade first. you save 610 resources by waiting.

How important is that? I dunno. that's 30-45 seconds worth of food/wood at that point in the game. also the more you make the more you would save obviously. not going to run the #'s on that though. If you are uber booming and no one is touching you, it's definetly better to wait until right before you attack.

I really should devote some time to test all this ramping stuff out in more detail. I've noticed that the cost to upgrade units changes rather dramatically. I've also noticed that it sure seems cheaper to upgrade in enlightenment age than in gunpowder age. I'm wondering if that's because I tend not to make too many archers (why, when I can make fire lances instead?) Since the enlightenment age upgrade also upgrades the archer line, it may have a reduced cost if you don't have any archers. Anyway, more research to do :-(
posted by Tim at 12:24 PM