I doubt that most people know this, because the whole ressource-system is really complex (overly complex?), but each time you build a ressource-generator on a node, the next one of the same kind will be more expensive.
for requisition-gens, the cost is 20 Energy, then 27 Energy, then 34 Energy etc. (for +60 req per second)
for energy-gens, the cost for the first generator is 80 req, 2nd is 96 req, the third 112 etc. (for +25 energy per second)
For more information about the ressources, this link is pretty useful:
Now, why does this system exist?
I think the initial thought was to make harassment of generators more beneficial: If you can kill a generator multiple times, it gets pretty pricey real quick.
But IMHO, all this does is discourage people from taking nodes and putting generators on them, since nodes without generators give you nothing at all.
This can lead to a very defensive and slow play style, which is already pretty strong in this game.
People should be free to take risks and get nodes and generators, loosing them is punishment enough, there doesn't need to be an added burden on what is one of the
main strategic elements of the game. We don't see every additional worker in Starcraft cost more than the last one, right?
What are your thoughts on this, am I not seeing something here, am I overreacting? I just can't wrap my head around this design-choice....