Hi,
our little one is now 15 months old. We don’t keep a detailed household account, but when I quickly scan through the bank transactions, I come to about 200-300 € per month in debits that go back to purchases for the little girl (diapers and stuff, powdered milk, and clothes). Then there’s daycare at 150 € per month and some savings for the extra expenses on vacation (with the small double room in the cheap backpacker hostel, you won’t be happy anymore with a child...) I would also say that 400-500 € quickly add up.
Of course, it also depends a lot on what you buy: we have a (otherwise very nice) neighbor who would never put her child into second-hand clothes and only constantly buys new brand-name clothes.
Others suddenly only buy meat at the premium organic market for 27 €/kg. (Although they themselves eat most of it...) Then you’re probably closer to 1000 € per month.
To be fair, you should actually subtract child benefit/child tax allowance from that, unless you really set it aside for the child.
Best regards,
Andreas