Old thread I know, but it is on the PBS. Mine cost $30 or $35 from a pharmacy.

Most of the cost might be getting it put in, depending on who does it. You need to see a GP first and then be referred to a gynaecologist (unless maybe you already see a gyno). In my case I went to a bulk billing GP and then to a gyno at the hospital so it was all free, but I did have to wait about six weeks to get in for an appointment at the hospital. Private gynos would see you faster but charge for it.