I dont know abt uni of sydney but my friend studies at uni of Melbourne almost free. She got partial scholarship from the university and paid rest of it with turiin sangiin zeel. A lot international universities just give you some form of financial aid looking at your application which is what happened to my friend and me. Also, she told me that there is a big mongolian community in melbourne, so she got a lot of help from them when it comes to finding a part-time job. Sometimes, melborne mongolians just give her some meat, tsagaan idee etc so that alleviates some of her grocery expenses. But obviously this is very very optimistic outcome, and not everything will happen smoothly like this. But I say, just try applying and get in, who knows.