There's never a firm answer to the question "how much money will I need?" but it's possible to work out a rough budget for yourself. Australia represents many varied opportunities for lightening your wallet, but here's a rough idea of what to expect.
Most travellers budget AU$1,600-AU$2,300 per month, depending on what type of traveller you are, how often you are drinking (this is where a lot of money magically disappears) and how many activities you do.
In Australia the majority of travellers spend the night in hostel dorms. Prices maintain the same throughout the whole year but availability becomes much more difficult over public holidays, especially Christmas, New Year and Australia Day. It's advised to book in advanced for these time periods.
The average price for a shared dorm room (mixed) is around AU$20 (AU$15-AU$25). New, flash hostels may be anything up to AU$35. If you're driving, campsites are an excellent alternative. Pitches cost around AU$30 with facilities, and that's split between your group.
The two main supermarkets in Oz are Coles and Woolworths. Coles 'smart buy' and Woolworths 'basics' are what you'll be buying, and a weekly shop can cost about AU$60 per week.
Eating out is cheaper than the UK, with a main costing anywhere between AU$12-20. There are lot of backpacker deals on eating out, and you can pick up the occasional meal for as cheap as AU$5.
Alcohol is MUCH more expensive than in the UK, and for this reason backpackers always steer towards cask wine, also known as 'goon bags'. They cost AU$15 for 4 litres of wine (if you can call it that) - it's an acquired taste...
Tap water is safe to drink, and keep a bottle or two to hand for emergencies - it's very easy to get dehydrated.
Australian nightlife is hectic, so be prepared to spend a lot if you're a clubbing fan. Always look into other things other than just clubbing. It's often a lot of fun to simply explore your surroundings at night. Surfers Paradise might be a bit too commercial for you but its neon glow looks particularly spectacular from the beach in the dark. Failing that, there's always the pub...
Australia has a big drinking culture, and you should never find yourself too far from a bar. Beer measures are slightly different in Oz - pints don't exist in a lot of places. Instead, depending on the state, you get half-pints, 'glasses' (around seven fluid ounces) and 'schooners', which hold three-quarters of a pint.
Hostels are a fantastic place for information on tours and activities. They also offer some of the best deals and if you're travelling on your own then it is a great way to meet like-minded people. However, Tourist Information Centres are even better. They are always welcoming and offer unbelievable deals that under-cut the hostels.
Obviously, the quickest way of losing money when travelling is by doing every activity and tour on offer. It's a great idea to plan what you want to do before you get there. You'll find yourself bombarded by different tour posters in every hostel you stay at. Always ask if there are deals on, or whether it is cheaper to book in a group. You'll be surprised at how often this works.