This useful information is from the ASIC site
Follow these steps to keep the wedding costs under control:
Work out how much money you need - decide how much you want to spend on each item - including food and drinks, venue, cake, cars and music - and come up with a total cost.
Start saving for your wedding now - open a savings account or a term deposit to earn a high interest rate on your savings. Use the savings goals calculator to work out how much you'll need to save each week.
Look for ways to cut costs - research online or ask around and find out how other people have saved money on their weddings.
Avoid using your credit card wherever possible - try to pay for big items, like the wedding dress or reception venue, in instalments so you aren't left with huge debts that can take years to pay off.