I wouldn’t want any more than 4 kids, partially due to costs associated with education, but also I’d like the ability to be able to spend time with my kids, play with them, take them fishing, to ball games, to see rabbanim, to learn with them, do homework with them, help them study, etc.
That is so wonderful of you. Since you want only 4, please don’t stop. Keep going. There are more childless couples than will be able to take all your “extras.”