Physiotherapy is a primary contact profession, so most people at Second Creek book directly without a referral of any kind. Where things get genuinely confusing is what a referral does or does not change about what you pay, because that depends on which of four different paths you are actually on, and clinics are not always clear about which one applies to you.
What follows is the mechanics of each path, plainly. What none of it includes is a dollar figure, because rebate amounts and covered-visit limits are set entirely by your health fund, Medicare or the relevant agency, not by this clinic, and quoting one here would only be wrong for most people reading it.