Do you know which of these organisations are respectable? Can someone recomend a good organisation? Which prices are acceptable for such an trip (1000 € for the flight, 200 € for the visa, 10-12 $ earning)? I don't have an idea.
What I can tell ,earnings between 10-12 $AUD per hour is absolutely too low for an adult.
Normally High School students less then 17 years old are starting their first casual job with $10-12 per/h.
There is an internet site where you can get some important info about travel & work in Australia, ....australink.pl . The best way to obtain details is from people who are already staying here temporarily on working visa.
Good luck