[Graeme Dice]

Originally posted by Cainehill:
This can be problematical - if you're running out of gold to pay your troops, summoned troops are usually the way to go, since most don't cost upkeep, while others do, and the documentation for the spells doesn't mention which cost ongoing upkeep.

However, the Summoned Creature Quick Reference contains the upkeep costs for every type of summonable unit. The ones with upkeep include both types of trolls, black hawks, and some of the units that you get with the crossbreeding spells.