You buy banks first because it will give you more $ for rushbuying immediately. It makes a HUGE difference, speaking from experience.
I'm not disputing that it makes a huge difference.
I guess what I'm saying is that the investment is also huge. Huge investment, huge payback.
Alternately, we could spend that investment on other things (such as convert it to research).
So, the task here is figure out which is better, depending on each game's idiosyncratic differences.
You buy markets/grocers because together they give you the same output as banks, but they also give you health and happiness in the city, which is always good.
I disagree that it's always good. It totally depends on the resources you have available, leader traits, wonders you have built, buildings, and civics.
Some examples:
-- you have a lot of food resources, you built the Hanging Gardens, you're Expansive, you've got Aqueducts in all your cities already because you needed them earlier, etc. What's the use of a Grocer's health benefit?
-- you founded 3-4 religions and/or have neighbors aggressively spreading their religions to you. You adopt Free Religion, and have already whipped temples (because you needed them earlier). Maybe you're running H-Rule, and have a lot of happiness resources. Again, what's the use of Market's happy benefit?
Frankly, I've found in quite a few games that I literally have to stop myself and say, "what the heck am I doing making markets/banks/grocers". I think there's a natural tendency (for me, anyway) to think more= better. More buildings are automatically good. When that often is not the case.
Wodan