Think link may help:
It lists several doctors in Sydney.
I'm sure you would be able to find some in Wollongong if you called around a few GP's. The maternity ward at the local hospital should be able to let you know of doctors in the area.
In regard to age and price, each doctor is different. Just call around a few to find what suits you.
Our first boy cost approx $400. Our 2nd was only about $100. If you wait too long (6 months), then they will most likely need a general which will be alot more expensive.