In my typical game, courthouses are mostly skipped (I find people overestimate them) and almost always Markets, Groceries and Banks (except in the capital).
Why?
Because they have huge opportunity costs. If you build Wealth instead, you will often get a tech that can be converted to gold and beakers via trade with much higher multiplier (and you do also get a tech itself
). For instance, Compass usually lands you CoL, Calendar and Construction.
Also, all of those buildings are built in an era where I get aggressive and then it is better (more efficient) to commit to units.
If tech trades are disabled (no fun) or you play Always War, Markets are worth far far more.
Usually, I get some breathing room for Markets around T120, so when I calculate Market or no Market for let's say 30
city, I will be in position that I can run 50% slider without trades for gold, failgold, GM missions. With them, I am at 80% slider. So, my Market will generate 0.2*0.25*30=1.5
. So, simple return of value says that you'll get your money back in 80T (if you had +25% OR bonus for building a building). Now, there is an opportunity cost which is map dependent, but if you invest into a building instead of simply wealth, you delay Oxford and Printing Press, you delay better units, you delay everything. Add at least 25% of opportunity cost. That is 96T now. since I typically win around T200, it will never have chance to pay for itself.
Ok, sometimes you get a lot of happy, but that is nothing you can't do with 3 warriors in Hereditary Rule, and those are the former spawnbusting guys you already have.
Bear in mind that 30
is a good commerce city.
In normal game, only 1 or 2 cities you build will pass this check for Market buildings and great AI cities you capture often keep markets, groceries and banks.
Courthouses also don't pass when I try evaluating them like that, however ORG leaders and large empires give them more value and also a tactical advantage of seeing research from high tech civ.