Late Game Building Yields

[CrazyG]

Maybe one of the problem is that we expect late game buildings to be "a lot of hammers => a lot of bonuses", which is essentially impossible to balance when there is not a lot of turns remaining. Cheaper late game buildings would be easier to balance.

This idea is pretty good.

I also like the upgrade in process efficiency, for similar reasons.

I think that buffs to tiles aren't really the best way to go, just because of close to game end this is. City building isn't a high priority. We should consider % modifiers.