Couple of small things i can add:

The lvl req ("overall need") for building "Shopping Mall" is all buildings lvl 8
The lvl req ("overall need") for building "Large Garage" is all buildings lvl 10
The lvl req ("overall need") for building "Sports Centre" is all buildings lvl 9
The price for building "Large City" Arena is $25.4mill

Those are what i can see in my builds atm - i'll post more as i get to them