I'm looking at a double DIEP reconstruction and just got some private quotes from a very experienced well respected plastic surgeon in oncology breast reconstruction in Perth. It requires breast surgeon (approx $500 gap) plus two plastic surgeons (approx $9500 and $10700 gap) plus anethetist (at least $6500 gap), the total coming out at about $28000 including $750 health fund excess. This is about what I was told to expect by the surgeons in the public system, so no great surprises.
I don't think I would shop around for prices, from what I've heard most of the more experienced surgeons will be similar and I think its really about going with someone you are comfortable with and who has strong experience and reputation in the type of surgery you are having done.
Revisions would be extra but I've been told that the most complex of those would be about $6500, and nipple reconstruction would also be extra but dont have any prices on that yet.