As it is now, upkeep multiplies new soldier/worker nursery base cost. This makes expensive ants become more expensive faster than less expensive ants.
tileBaseCost * upkeep = tileCost
This can cause wood ant ranged nurseries to cost 1000 food more than wood ant melee nurseries, thus making it important to build the most expensive nurseries first.
Using another calculation method should remove this:
tileBaseCost + upkeep = tileCost
It just adds the upkeep to the cost, so all tiles get more expensive, but the price difference does not change.
tileBaseCost * upkeep = tileCost
This can cause wood ant ranged nurseries to cost 1000 food more than wood ant melee nurseries, thus making it important to build the most expensive nurseries first.
Using another calculation method should remove this:
tileBaseCost + upkeep = tileCost
It just adds the upkeep to the cost, so all tiles get more expensive, but the price difference does not change.