C.
I have an almost 4 year old (in Jan.) and a 13 month old. We budget $450 for most months but $500 for November (bec. of Thanksgiving) & $550 for December (for Christmas party, etc.). We are probably on the low end of what you will hear considering diapers, wipes, and formula (when we used it) came out of this as well (contact solution, shampoos, etc.) too. Good luck!
C.