You probably wouldn't notice unless you were playing Sparta, but the Marble line of buildings is worthless past L2, since the income of 175 at L4 is not worth -8 food and -10 public order.
I've fixed it to match other L4 resource settlements - 100 -> 800 at L4, just like Silk.
You can find the fix here:
http://steamcommunity.com/sharedfile.../?id=391066057