I think every family should have as many, or few, children as they desire. Congratulations on your choice. Most of my friends have at least 4, some have even up to 7.
It really isn't much different having more kids, they just have someone to play with all the time. Cooking for 6 is not much different than cooking for 5. I tend to use the same food for all ages but just use my Pampered Chef Food Chopper A LOT! I can get the food in timy peices for the little guys and still have an appealing meal for the bigger ones. I make a lot of stuff from scratch instead of buying processed frozen stuff. I always have my eyes open for large pots or pans that help me out, like good quality pizza pans. The cheap aluminium ones don't last and I make lots of pizza. I can make several and each person gets what they really like.
As for clothes, they just get handed down, we do get a few things new occassionaly but my friends seem to always hove someone growing out of a coat or a bunch of jeans. To me, doing the laundry and really taking good care of the clothes is the best way I can cut costs. You can sort them into tubs and label them...boys size 2 Winter, girls size 5 early Spring/Easter, girls size 4-5 Fall and Halloween tees and sweat shirts...I tuck them under beds, in the bottom of closets, on shelves in the garage, I have found all kinds of hiding places.
One of my best friends has 7 kids and she is a Professor of Nursing. She has good systems for teaching chores and cleaning to all the different ages. They are almost every 2 years, one is off by a year. The older kids have the responsibilty of teaching a middle kid the way to clean "Their" assigned room. For instance, a "big" kid may have the kitchen for their chore. The older kids are over 8 years old. They have a "little" kid assigned to them. The mom has the chorelist posted inside the kitchen cabinet door. The big kid is responsible for loading the dishwasher, washing any leftover dishes, sweeping and mopping if needed, taking out the trash, wiping the cabinets down, etc...they can delegate as needed to learn how to manage getting stuff done and asking for help. The little kid has the responsibilty of loading the lower rack of the dishwasher, putting away the dishes that go in the lower cabinets, wiping out the fridge if needed, etc...little bitty kids, too little to have a chore, can be a helper by putting up the silver ware, it teaches sorting and hand washing. An adult is always in the kitchen, and playroom too, because those are really BIG jobs. That way the family learns to work together and be helpful and have a clean home.
She has a list posted in some part of every room and it is very simple for the kids to check to see if they got everything they were supposed to do.
It is truly a blessing to have a large family.