Since April 1 2018, PrEP is subsidised by Australia under the Pharmaceutical Benefits Scheme (PBS). Thus, it costs $39.5 per script ($6.40 concessional rate) [0, 1]. Earlier, it could cost as high as $10,000 a year [2].

[0] https://www.healthdirect.gov.au/blog/Anti-HIV-drug-PrEP-to-b...

[1] https://www.healthdirect.gov.au/pharmaceutical-benefits-sche...

[2] https://www.theguardian.com/australia-news/2018/feb/08/hiv-p...