woo exciting!! ok so a rough guide for you as to what is going out in our house. This is for 2 adults and 2 children (so may help with DP having a child too)

Food: 170 a fortnight including meat and fruit and veg
Electricity bill: 400-600 per quarter varies quite a bit on the time of the year
Water: $30 per quarter
we are on bottled gas so cant really help with that

We have our house phone so that its only connected to incoming calls and i have a great cap plan with optus very affordable and you dont have to stress about having to come up with money for a new phone if yours breaks. Also we only pay $50 a month for our net and it gets very good gb's with telstra we were paying around $80 for 12, i cant remember what we get now but its more than 12!

HTH and fingers crossed for your house hunting