I live in Brisbane.
If you are earning in ozzie dollars, you HAVE to ignore the exchange rate. Dh earns 2.2 x what he did in the UK, so we use the 2.2x modifier, which is pretty universally used.
We pay $1200 a year for gas, electric and water. We don't use the air con other than occasionally (for when it's above 30 degrees at 9pm) as we have a high set house and make the most of the passive ventilation. We use the BBQ for lots of our cooking, and a $28 bottle of gas will last us about 3-4 months. We still cook in a similar way to when we were in the UK (when we were absolutely piss poor) where we'll batch cook a curry/spag bol/chilli and freeze it. The advantage is that we have space for a bigger freezer in Aus.
In the UK for the same period last year we were paying 150 pounds a MONTH for our gas and electric.
I'm astounded at how much people spend on food here. In an average week, we'll spend $60 in Aldi, $30 for fruit and veg at the local Charlie's fruit market, $20 on meat in the butchers, $60 in Woolworths/Coles and then probably $10 on lunches and about $25 on a takeaway or fish and chips at the beach. This is for two adults, a 3 and 5 year old (the 3 year old is in nappies) and two cats. I'll sometimes do a $30 top up shop as well, but not always. We never buy fruit, veg or meat at the supermarkets, it's just too expensive. Any fruit, veg or meat we do buy is in season. I got a side of lamb (a shoulder, a leg, 6 chops, 8 forequarter chops and some ribs) for $25 from the local butcher the other day - good quality, new season local (well, same state) lamb. If you don't believe me, I'll happily email you my receipts :)
My weekly travel to work and back costs $40. We live a 15 minute walk from the nearest train station, where the trains run ever half an hour to the CBD. The equivalent commute from our old house in the UK to Leeds city centre would have cost 35 pounds, or more if I had to get a bus at either end. (Brisbane has an integrated transport system so costs are per journey, not per leg of each journey - I could get the bus to the station for no extra cost if I wanted, but I prefer to walk.)
Our initial outlay of buying a car was $32k - the equivalent car in the UK (Mazda 6 estate) is 16k pounds, so not much difference using the correct modifier rather than exchange rate, although we bought the car with UK savings, so it could be said we lost out there. Second hand cars hold their value much better in Aus, but in comparison last much longer than UK cars. We live in suburban Brisbane and have no need for two cars, any more than we had a need for two cars in the UK.
For clothes and homewares I shop in Target, Big W and Kmart, with the odd shop at Myer and David Jones (whereas in the UK I would have shopped at the supermarkets and Primark, with the odd shop at M&S and Next).
Our biggest expense is daycare. We're on a 457 visa so get no rebate from centrelink. We pay an average of $80 per child per day, but that is one of the factors with both parents working. It would be the same in the UK as we never had family nearby to babysit. We are applying for PR soon, and as soon as that comes through we will get a 50% rebate on our childcare.
You only have to pay for schools in NSW - education in the other states and territories is free, although like people have said, uniforms aren't cheap ($22 for a school polo, $16 for school shorts) and for DS in prep we have to pay $90 to cover his materials.
People see what they want to see, and you'll find the grass is greener on the other side of the world - the longer since you've been in the UK, the greener the grass is over there (and not just because we've had no rain in Brisbane for 45 days ;) )