I went through an OB for my DS (first baby) and had the first visit payment (around $115 - partly claimable) and then the gap fee of $1000. He did the 12 week scan in his office but the 19 week scan was done externally which cost around $300 and something and was partly claimable (I think we got back around $180). I didn't have to pay for blood tests they were through Medicare (used Mayne).

The only other things were our hospital excess and the pediatrician ($350 all up - partly claimable)

My OB was listed as a no-gap with my health fund but stated that tey weren't, but then again he was cheaper than a lot around us.