@oniyide
I am pretty sure each Civ3 expansion was 40 bucks when it was released. First expansion (Play the World) included 8 races with their new units, ability to play Civ3 online (first Civ3 couldn't), and 4 new game modes. The second expansion (Conquests) included 7 races with their new units, new religions, new disasters, techs, wonders, also with a few custom scenarios that included in those scenarios (85 new technologies, 50 new units, 60 new buildings and wonders, 30 new resources, more than 8 new governments, these are just for the scenarios not regular game).
So basically for about 80 more dollars (if you bought them right when they came out) you got 15 new civs with their units, new disasters, tech, wonders, more game modes, ability to play online, new religions, custom made scenarios with unique units, buildings, wonders, tech, etc..
Now with Civ5 if you buy each race at 5 dollars a pop. 80/5 =16 races with unique units and 16 scenarios
So basically by splitting the DLC to just one race a time they don't have to worry about including new resources, techs, wonders, governments, etc. They can just include that later for more.
