Excellent idea. I've already added the overflow

and

, and this would make a great complement to them. How are these for wording?
- +100% cost for new build
- +200% cost for Oxford University
- -33% cost from Buildings [Kremlin]
I don't really like the first one, and I'm not sold on "cost". I'll have to look in the SDK to see the game mechanics. Perhaps I should add the full calculation of the cost to the hover since the production modifier also affects the cost.
Edit: Wow, the hurry cost penalties are multiplicative! The above could be misleading, though I think prettier. Should I switch to these:
- x 200% cost for new build
- x 300% cost for Oxford University
- x 67% cost from Buildings [Kremlin]
Drop the "x"?
In the espionage list, you can also see the various modifiers to cost. These are almost all multiplicative (except the ones caused by religious bonuses) however, they're all mentioned with +x% and -y% signs which makes it seem as if they're additive. So I would really like to see the multiplyer signs here so that it is clear for the player.
You could also use decimal multiplyers:
x 1.5 cost for new build
x 0.67 cost from Buildings [Kremlin]
etc.
It's actually weird to multiply a value with a percentage. As a mathematician it really annoys me, but I see it at more places in the game, so I have learned to suppress that feeling.
Hehe, and I was editing mine while you posted.
We're both thinking while we're writing.
First, note that I'll use the correct constants variables when I actually do it. These are just samples. Hurrying a new item is governed by NEW_HURRY_MODIFIER which you say is 50. I never hurry a new item, so I was just guessing.
Oh and here I thought you just really didn't know what you were doing.

I was just providing you with the values, but you will of course take them from the variables that define them so that it works well with mods.
While the base

/population is constant (based on gamespeed), once you add in production modifiers the

you get varies based on the number of population due to rounding. This is always annoying.
I would prefer a decimal number with 2 decimal value.
Example: Pop/gold rushing a normal building at epic speed while having a forge. The building is at 50/120

.
At epic speed, you get 45

for each pop point. The forge gives you a 25% bonus (or a multiplyer of 1.25

).
I'd want the following information:
costs 2 population, 112 hammers
hover info: efficiency 56,25

per pop
costs 210 gold
hover info: efficiency 1

per 3
In this case, there are no penalties, so I would just leave them out. You could choose to show the hammer bonus from the forge in the first hover. That bonus is also clearly visible in the actual production calculation before the construction bar after you've applied the whip.
This dovetails into my original plan long ago (year and a half?) of having a bar that would show the various population points so you could reach a threshold without going over. Yes, I could show how many

you'll get whipping now, but I also want to see how many

I'll get for 1 less population so I know how many more I can add before whipping to maximize overflow.
You could indeed show the hammer output for different numbers of population whipped. It could then become a long hover, especially for world wonders. Maybe limit the hover info to: current pop number (the number that would be used now) hammer yield, current pop number -1 hammer yield, current pop number -2 hammer yield.
If you can't whip because of a shortage of population:
maximum pop number (the maximum allowed number of citizens that you may whip) +1 hammer yield, maximum pop number hammer yield, maximum pop number -1 hammer yield.
So if you're hovering over the pop rush button while building the colossus and you don't have enough population to finish the rush (say size 9 city, max pop rush size = 4), you could still get something like:
efficiency 33,75

per pop
168

for 5 pop
135

for 4 pop
101

for 3 pop
warning: x 2.00 cost for rushing the Colossus
(using a times 2 cost modifier for rushing the colossus and a times 2,25 production modifier for copper and a forge and a base of 30

per pop at normal game speed. I didn't look up the cost modifier for rushing the Colossus, could well be 2,5 or 3.)