Congratulations on your pregnancy.

Will the private ob deliver you in a public hospital? If not, you will also be looking at private hospital fees, which are very expensive without PHI. Then there is the consideration of whether either of your babies will require SCN, which will cost more again in a private hospital. Ambulance transfer from private to public hospital if either baby requires a NICU... a whole heap of possible additional costs.

If your ob of choice will attend to you in a public hospital, have you checked whether the hospital is agreeable to that? A public hospital usually uses whichever ob is on duty/call if required. I'm not sure whether most hospitals would be agreeable to making arrangements for you to be attended by your own ob? If the ob has delivery rights at the hospital, I imagine it is possible, but I would certainly investigate before paying any money to the ob.

Lastly, Medicare only rebates a small amount from the obstetricians fee. From memory, we got a total of less than $500 back from Medicare for my obs management fee. We were OOP about $6K... with top PHI.

Well, that was a bit of a downer... sorry! I would encourage you to investigate all options and possibilities before you commit to a plan for the birth of your babies. How lovely of your MW to waive her fee! I hope you have a beautiful birth.