@ritterpa
Yes, that is certainly possible, it would just be a matter of changing a few things in that excel file of mine, and then editing the iCost values of the techs. Here's what I'm worried about though:
A) Will this have the desired effect? It would have to be a fairly substantial change. In my one test game so far, the finances hit me hard, but not until early classical - throughout ancient I was at 100% and still making money (playing on Noble). Inflation hadn't kicked in (I gave it a wide berth in my GameSpeed file), so I was really just operating on the coins in my cities, to pay for my buildings, units, and research. I also felt that the pace was EXCELLENT, much improved even in the ancient ages.
TANGENT ALERT: A lot of what I'm going for with my mod is to have better tech-cost BALANCING. I hate that you can travel five or six techs down your timeline before having to make a serious decision about whether it's wise to research another advanced tech on the same path, or catch one of the other disciplines up. What I mean is, you often research a 4th- or 5th tier tech for only slightly more time investment than a 1st- or 2nd-tier tech, which in my mind doesn't do enough to promte a well-rounded Civ. Making tech more expensive but also making cost [increases] from tier to tier more severe is a large part of my goal, so that you can research four or five lower-level techs in the time it would take to get the ONE at the frontier of your technology level.
B) So I'd like to preserve that, which means incrementally increasing the increase (as it were) in the original costs. Which means I'd have to drastically reduce the cost in the very early techs, which would break the mod for that time period.
C) Would that actually work? If you reduce the cost, you'd basically be saying - now you can choose between spending your money at a more reasonable pace (smaller percentage research for same amount of progress), or losing money at the same pace as before in order to get more tech faster. And maybe that would turn out to be equally (if not more) viable - you might find that your earlygame stockpile from goody huts was enough to get you through the tech quick enough that you could get to commerce or banking or something without sacrificing research. I'd be especially worried about this with the AI - are they really going to take their research down just because I've reduced the costs? I think it's unlikely, but couldn't say for sure without testing.
What about the opposite approach? What about increasing the cost of early-game tech, so that players HAVE to budget their research percentage or go bankrupt? I'd love to see a design in which a player was rewarded for intelligently managing their research. i.e. if you could balance the game in such a way that a player who cranked research was quickly stifled financially, preventing them from expanding efficiently, and thus set back technologically in the long term, I think that would be the best solution. But would increasing costs really have that effect? I think as a player I am always trying to be on the leading edge of technology, and will scramble to get ahead if I see a leaderboard that doesn't have me in the top 3 for "most advanced," so I may not be the best person to test that. Intellectually it should work that way - fall behind early to build a stronger infrastructure and leap forward to trounce everyone later on - but I'm just not convinced, so I always play the rat race with all the other Civs.
I think I've written enough for one post. ritterpa, I like your suggestion and think it bears testing, but I do obviously have concerns.
And I still don't have any better plans for long-term income/cost improvements, to make an epic gamespeed that can truly accomodate more units and cities. Such a solution would have to span all ages. I can try my idea of giving some tiles more commerce, but I'm sure there've got to be better solutions out there.