Is there an advantage to building multiple trade starbases, ie....
Do they stack if I have 2 next to each other with + to trade routes.
How about if I have 2 with +prod/research next to a planet.
Do the +trade route starbases give more bonus if there is more of their incluence circle covering the trade route?
If I have a +prod/research starbase affecting a planet... say for example +20% and the base planet research is 5, so it is now 6 with the effect f the starbase, is the extra point of research a *free* bonus, or does it cost me money too?