Diapers alone can cost around $100 a month. Add
formula to the mix and it's a hefty monthly bill. The good news is that for subsequent children (especially if you have another of the same sex) you're probably already stocked with tons of baby gear and clothes, so that will be a savings compared to the expenses with your first.
Shop around in thrift stores for any furniture or big ticket items you might need. If you have a friend or family member pregnant with their next child, consider doing a clothing swap to freshen up your baby's wardrobe or to stock up on clothes for the opposite sex if you need them.
Do keep in mind, though, you may need to replace some of your gear. For example, the American Academy of Pediatrics (AAP) recommends avoiding older, used car seats to ensure maximum protection for your child. Most have an expiration date printed on them and if they don't, the rule of thumb is six years from the manufacture date. The AAP also recommends using cribs certified by the Juvenile Products Manufacturers Association.