haven't tried 0.86 yet, but as of 0.85 I don't really mind the cost of Items I suppose ....
However, economies should possibly be more flexible, more unique, more entertaining.
Give a national building (fairly cheap) that allows for +5 growth in one city.
Give a national building at tier 2 of Civ tech tree that provides +1 grain.
As units grow, give us choices about Research vs Production ... maybe a building that gives -20% production and +40% research versus a building that gives -20% research and +40% production.
Maybe give us a building which decreases the Maintenance cost of newly built units?
(Mass Wave tactics should be the one ... and perhaps the only advantage of horizontal growth)-> other than the inherent bonus of having more population.
It should be possible to focus on one city and make that city get to size 4 or 5 rather quickly, while the rest of the empire is only at size 1 or size 2.
Maybe a national building or spell which increases one City's grain by 2 or 3, and reduces the grain of all other (owned) cities by 1?