Australia is so far away that we can get there in different ways. There is no direct flight from Europe. But it is hard to find return ticket cheaper than 800 Euro, unless some promotion. Planes usually fly with a stopover in Kuala Lumpur, Singapore, Bangkok, Doha or Dubai. But you can also fly through Johannesburg or America. However, always for a relatively small fee you can use stopover on the way and see something extra. It’s worth to sign up on frequent flyer and collect miles, we might get free ride later on. I had a lot of time, so I went from Poland to Australia overland through Asia. You can also try to combine cheap airlines from Asia to Australia. Search on Tiger Airways, Air Asia (connection even from London or Paris), JetStar or Virgin Blue. Besides, it is worth looking for cheap flights from Europe on the pages of Expedia , Cheaptickets or many others like them.
Remember that you not allowed to bring to Australia food, seeds, wood products, animals etc. More information can be found here.
After completing the first year of college, I changed my student visa for tourist and began intensively explore the continent. I also decided that I will return here to continue my education, and the most interesting solution was to buy round the world ticket. More on that I have written here.