In Civ5 and CivBE we have that, 5% more cost on techs and civics for every city you have. This reduces the power of domination by penalitizing the benefits from having lots of cities. Shall we inherit this? In fact I don't know why they give up this feature. They really shall inherit this from Civ5 and CivBE. An implementation: We start at 100% cost, and eureka/inspiration provides 50% cost of techs/civics, when you settle your first city all of your costs become 105%, then follow by (100+5n)% cost if you have n cities. However, eureka/inspiration still and always provides 50% of the base cost. So if you have 20 cities under this rule your cost of techs/civics will be 200%, however eureka/inspiration still only provide 50% so you need to research the following 150% yourself. This may help reduce the power of domination and make small empire compatible.