I travelled that same route last year and paid 15,500 SEK which at the time I worked out at about 1,500 euro r/t.
The stop at SYD that day was almost two hours. Landed at 06:09 and airborne again at 07:59. They make you disembark at SYD and do immigration. I didn't look for a lounge. On the SYD-CBR sector all they had was coffee - they said all the catering had been removed.
On the return, the landing at SYD was about 14:30 and we boarded again at 15:50. I used the QF First Class Lounge at SYD which was excellent. Very varied dinner menu with table service. Good wine list too. Can't remember if I got that lounge because of the QR busx class ticket or because I am OW Emerald. Hope this is helpful.