To feed a baby for a month it's going to be around $200, that varies because every baby is different so it could cost more. Diapers cost $40-50 a case. you can never tell how many a week simply because a baby will mess them up a lot, so you will go through a lot. Wipes aren't that expensive. Best to buy formula, wipes and diapers at SAMs club. By the bulk is better. Clothes aren't cheap and they will need a lot of them.
Babies are expensive. You have to supply diapers. ( 6-8 a day) formula, clothes. Not to mention the crib, blankets, bottles, car seats, bedding, doctors appointments. Stuff for your baby's hygiene. The list of items you will need seems endless.