Agree with the above. The qantas lounge in perth is crap. The best you could hope for is a toasted sandwich or some nice soup. The international terminal is undergoing renovations so it's crap also. The qantas terminals have better shops.... Well a few and you can take the airport bus to get round there for free but my first pick would be catch a cab to Murray or hay st to shop eat chill out. About $40 fare. There is nothing in the region walking distance of interest. Get back in time as customs is incredibly mind blowingly slow to get through.

Hmm if you're coming air nz you'll be landing 5pmish, take in a movie in town or book a cheap hotel to snooze at on wotif. They have some good rates some with gyms or pool etc.