I think 1BC/module is harsh, but yeah, some increase in Mtc cost is needed Based on installed modules.  Economic star bases focused on economy only, should pay for themselves with profit on a world where a majority of pop is focused on economy. Not in front of the game know how much that is, but each individual module gives on average 10%, no?  You need 5 modules to eve approach the abilities of a single building.  buildings will always be the most efficient in regards to mtc.  I'm thinking 1 BCbase and 0.25 per module, off the top of my head. 

GC3 is a Starbase management game with a 4X tacked on. 

Okay, flippancy asid, the Starbase system is the weakest part of the GC3 arsenal and the devs know it hence various comments on assorted dev streams indicating that SBs will be reworked.  Or at least the constructor spam side of things will be, which may have a restraining effect on SB spam in general - I hope!

Are you confusing this with manufacturing vs total manufacturing?  I was certain that it added a 10%, along with my at the time, 600% I had on the planet, meaning I needed 7-8 modules to match a single building ( i didnt yet have the highest SB techs).  Same for the research labs I added, VERY small gain each module.  Yes, it was worth it, but was going to TAKE A LOT.  Approval modules actually seem to be the best bang for the buck.  

So total manufacturing applies to all base production, no matter where you divert it to, manufacturing, research, or science?  I suppose I am confused. Not the best name choices, considering no tooltip to show the details of total manufacturing calculation

I wasnt in front of the game, and now I am, I see that the basic economic ring only provides the total manufacturing.  The statements I made where "several" where needed to be equal to a building was relating the the higher tech modules, be it research, manufacturing, or economic.  I saw the bonuses clearly in the tooltip on the planet, and thought "ok, thats nice, but that will mean a lot of starbases to make a good difference".  

Thanks for the clarification!

I know that Paul stated in the last dev stream, that in addition to planetary governors, they are looking into starbase governors (if in GC2, he certainly should know, I'm new to 4x, I have no clue!).

No idea how SBs apply to a fleet's logistics in GC2, but I think that a slightly increase mtc cost would help offset some things.  Currently, if you crazy spam SBs on a planet, its certainly worth a few buildings worth of near zero mtc costs.  I think its the micromanagement is what prevents a lot of people doing it, as the default constructor called in is NOT your special low cost constructor.  A proper SB Manager needed for sure.  Even though I play pragmatic nearly most of the time, as well I think there should be some scaleable mtc cost to the SB.

That and one would have to start paying an arm and a leg to build them.  If one went over the cap, each starbase cost progressively more to build.  Especially frustrating if one had to destroy a SB for any reason.

The funny thing was, it was implemented, partially at least, in a percentage based formula (that I never bothered to learn).  Get the cap high enough, and one could build unlimited starbases since one was getting over 100% of them free.

Well, I'm now convinced that large logistics fleets is OP against the AI, as it doesnt seem to care much about it.  If anything, the AI needs a logistics boost in more difficult levels, and they just need to get the AI to keep its ships in max logisitics fleets, period, unless in an "absolute" safe zone.

Star base spamming is from using them to offer support to planets.  You as a player, can only mine 1 resource (or relic) with a starbase, even if you have multiple overlap.  As well, if its already being exploited by another faction, you cannot use it, until the other faction's SB is destroyed or decommissioned.   That's one of the good reasons to trade SBs.

Mulit-overlap is "unlimited" (as many SBs as you can cram, as long as you keep each SB 5 hexes away) for planet support however, fitting 5 SBs with normal SB Range (of 5), and even more if you have extended SB Range (7, then 9).  So, you can literally have 8-10x more starbases than planets, in your empire.  That spam is quite salty!!

diminishing the returns would be the best solution, if they want to add one.  Taking an average makes no sense, it would just implicitly cause everyone to build specific focus SBs, which was your first suggestion.  

Its not a terrible exploit by any means.  The constructors required to make such SBs can get expensive, and divert from other production.  I think the real problem is the simplistic mtc costs they have, it should be module based by the least.  

Well, request constructor works fine, with the exception that it takes your stock constructor, not one you've optimized with more constructors, far less range, or even less movement.  Once they have some pop up to let you pick which constructor to request, I think it would be great.  Then of course auto installing once the constructor arrived.  These issues will all be taken into heavy consideration for the SB Governors they have talked about, in 1.2 or 1.3.