This is is what i know..
Tafe is to become an enrolled nurse, they earn roughly around $30,000 (going up per year). Enrolled nurses get stuck with the undesirable things like washing people.
Uni, you become a registered nurse they earn anything from $34,000 up, increasing each year. Being a registered nurse you get much more responsibilities such as medicine, as well as the opportunity to specialise such as working in surgery or as a midwife etc, if you specialise you get paid more.
After you have enough experience (and i think another qualification) you can become a unit manager, which your incharge of all nurses in your unit (like the head nurse in maternity ward), they can earn around $50,000.
Then after that there is a nursing manager which can earn up to around $70,000.
There is pretty much endless opportunities as a nurse as there are nurse educators, consultants, researchers or if your lucky a nurse practioner which does alot of the same stuff as your local G.P.
Basically with more experience and qualifications you get the higher you can rise. After 8 years in one position, your pay stays the same.
I think many just stay in one spot because they become comfortable where they are. My boyfriends dad used to be a registered nurse for 16yrs, but didnt want to continue going up, and he says thats a common thing. You just got to keep learning and gaining experience, to go onto higher things.