Playing around with a few production queues in my current game, I've found that it costs 17.5 credits for each industrial sectors used to create a starship. It costs about 8 credits for each each industrial sector used to create or upgrade a structure.
actually this depends on your bonuses. if your bonuses are 0, it's 1 BC per production unit (include research). bonus production from a high score costs .5 BC per unit of production. since you get at least small bonuses from many different sources, how much an industrial center or discovery sphere actually costs you varies from game to game, planet to planet, and turn to turn.
Yes, I know.
I listed my bonuses that affects the cost per week in my second paragraph. 20% for military and social production bonuses due to an Industrialist political party. Another 20% to military and 30% to social production bonuses due to custom race bonuses.
The planets I used to check had no bonuses whatsoever. There is no bonus from military or social production focus. No "negative bonus" due to research focus. And finally there are no bonuses from nearby economic starbases.
What do you mean by:
bonus production from a high score costs .5 BC per unit of production.
???