First double the costs of all factories. This is to represent investment in infrastructure to support the factories. For example housing and entertainment for any in house people paid to stay and work at the factories.
Arent the factories mostly automated. Atleast compared to current time (and lets face it, automation is already major in 2014). Compared to the profit each factory puts out, the minor human infastructure and such would probably be pretty insignificant in cost.
I will say that the idea of Batarians being indoctrinated by the Leviathan of Dis would make a lot of sense. All the new tech Revy is inventing HAS to be a major concern for the Batarians as a whole. I mean I would think they would be concerned about a potential offensive by SA possessing far superiour technology. Unlike the Asari, the Batarians don't have a prothean beacon, but they do have that corpse of a reaper, and rapid tech advancement of humanity could well convince the Hegemony to speed up the timetable there.
Furthermore, Sovereign stated in ME1 that one of the major reasons why the Reapers leave the mass relays and the Citadel behind is to try and control the direction of technological development. An absurd prodigy like Revy starting to invent incredibly advanced stuff must be worrisome to Sovereign. Especially given that we know the Reapers are already late due to the protheans modifying the Keepers. Which basically means that the galaxy is ALREADY too far advanced as far as Sovereign is concerned. And that was before Revy.
Would make perfect sense for Sovereign to manipulate a few Batarians into getting the Leviathan to try and disrupt the development of SA. Heck, would even make sense of the collectors gave the Batarians a few minor tech advantages to try and keep SA down while Sovereign plots to summon the rest of the reapers.
Basically, Revy is a clear and present danger to the Reapers, and there IS an active Reaper in the galaxy with the ability to mind-control people. Once Revy starts pushing out factory after factory producing more and more super-tech, Sovereign should really do something about it. I can understand Sovereign not wanting to reveal itself openly and personally attack Revy, but I would expect it to be smart enough to basically start doing lots of things in the background to try and make things difficult. And with indoctrination and a puppet spectre, Sovereign should be able to do a lot of things to slow Revy down.
I mean would it really be reasonable for us to believe that Sovereign will just sit there and watch, as the galaxy gets more and more advanced tech and the edge the Reapers have in power grows smaller and smaller?
Ultimately, Sovereign and the reapers are the REAL enemy for Revy and everyone else. Asari, STG, Cerberus, Citadel, Heretic Geth and whatever are just the minor bosses to be faced on the way to the real end boss.