Do you really believe that playing Tradition is better with just 1 city, than like 4?
If that's true then after those 100 turns you are in better situation than with only 1 city and it's get better. And a game is usually like 300 turns? I don't really follow your logic...They need at least a hundred turns or even more to be worth 10% increase in cost not to mention you need to sacrify growth and production for those settler, which mean losing some key wonders which is very important early as Tradition.