While psychology is key early on, every experience is different. The range of what you might feel, not" you will", and where to ask for help. I was terrified of mounting costs (after being stung big time in by using private health 9 months ago for a broken bone), and found surgeon super helpful. Happy to put me on public list instead of private, got every bit of info on out of pocket possible. But, it was imaging pathology, that were still unexpectedly $$$
Ended up private, and other than surgery, pathology (now in chemo,) my health fund is paying up, and very happy with care, direct access to own oncologist being maybe a defining factor. You can switch between systems, decision you make at the start doesn't mean you can't move systems, or hospitals, whatever.
Things move so fast in early days, take time to consider, regroup, 2nd opinion if you need it - reassure that breast surgery is not an emergency.
Making decisions about recon etc in that headspace - how to put your own feelings about it to the fore. I opted to deal with that at the other end of the journey (if at all), and very comfortable with that, and the lesser risk of complications etc.