I plan to put all the money received in the 'baby bonus' ($3000 or $4000 depending on when I fall pg) into my OB fee and tests/hospital excess. That way I am happy as I am getting the cover I want and don't have to budget as I will get the money back when baby is born. I couldn't care less about the private room in a hospital but want the Doctor of my choice thoughout my pg and delivery.
I have rang many OB's in Melbourne and they seem to range in price from about $2000-$4000 (out of pocket) but you can claim once over threshold as someone said above. Also, I will have any scans recommended by OB.

HTH.