Less than $500 is all you need to build a fully autonomous flying vehicle. It helps if you can write a spot of bug-free C code though and testing it could be slightly cumbersome. There's a few HIL solutions for the initial de-bug though but that will only get you so far.
Really though, if it isn't this, it's another method and making something illegal isn't going to stop it - the data to build thsi stuff is already out there. Heck, you can write some code for your Android telephone to control your UAV thesedays and have it ring through a five-mile call to the destination...
I hope Australia isn't stupid enough to tie this growth industry all up in useless red tape.