I haven't actually played with this mod yet, but the description looks like all good stuff. I just checked the data files for some of my particular grievances, though, and you missed one: cost scaling of the Industrial Sector.
You hit the prices of the high-end research buildings fairly well, and the bank, but the top construction building still has its way out of line unmodded cost.
While I'm on the subject of price progressions, though, I think even for research and banking it still needs some tweaking. In a game designed to handle it, the current model with tradeoffs for high space efficiency would be good. As is, however, the game interface and automatic upgrading mechanic are clearly based around the idea that any more advanced building is automatically better in every way. If you have Research Centers, Xeno Labs are now an outdated relic of the past, and likewise for any other new/old pairing. It is technically possible to build the obsolete version and prevent or delay upgrades, but it requires a lot of micromanagement.
Given that interface design choice, which I think is beyond the reach of modding, the tech progression should be designed so that that assumption is in fact correct, so that extreme micromanagement will be neither necessary nor beneficial. As it is, in both the unmodded game and this mod, it is not. Higher tech buildings produce more per tile, but typically less per build cost (the first few industry buildings keep the cost-to-production ratio constant for a while, but that's it). For about the first half of the progression industry and research improve production per maintenance cost, but then the trend reverses.
I suggest a progression as follows:
Industry costs 12.5 per point to build, 1 base plus .5 per point to maintain. This matches the Traditional Factory, Xeno Factory, and Advanced Factory, requires a minor tweak of Manufacturing Center, and a major change of Industrial Sector (which is extremely out of line any way you look at it).
Research costs either 7.5 or 10 per point to build, and 2 plus .5 per point to maintain. This matches either the Xeno Lab or the Research Center for build cost (there is no stretch of constant cost ratio here, unlike for industry), and Xeno Lab through Research Academy for maintenance.
Banking... on review, I think banking is actually ok. It holds steady within a narrow margin of 4.5 build cost per percentage point of bonus except for a slight extra for the Stock Market, but you get a free influence bonus extra on that to compensate. Maintenance is constant at 1.
With this model, the build cost ratio would remain constant throughout the tech tree, while per tile output and maintenance would always improve. With this, unlike with both the default game and your current mod, I would actually be content to always build the latest of these types of buildings.
I haven't looked at any race-specific buildings for this, but for thoroughness they should also be checked and potentially tweaked to follow similar progressions.
Good work on all the rest, I'll enjoy trying it out over the next few days.