A thought is Rebel Gun Works:
https://www.rebelgunworks.com.au/They are in Woollongabba, so slightly closer but not as cheap.
As far as brands, I have had poor results with Remington brass for reloading, and ho-hum results with Highland ammo (Though after a lot of post-processing the brass, it has lasted well in reloads). I also found the Hornady 'Match' brass seemed to have a bit of a crimp around the primer, which needed a bit more force to de-cap them.
As far as ammo you can buy and get good life out of the brass afterwards, I am finding the OSA/Buffalo River (Which is ADI) brass seems to last well, and pretty decent value for money.
Federal brass lasts okay, but not as consistent or as long-life as the OSA brass.
(Slight divergence here) Of the brass I reload, the Lapua and Norma brass is the most consistent and most uniform. If I weigh loaded cartridges after I've finished reloading them, both these brands of brass rarely vary by much more than 2 grains between loaded cartridges, with an average weight around 375gns loaded (.308win). The OSA brass varies by slightly more; maybe 2-3.5 grains, and the Federal brass maybe half a grain more again.
In contrast, the Highland brass can vary by up to 10 grains.
(The reloaded Highland brass varied so much I weighed a heap of empty Highland cases to satisfy myself that it was just variation in the brass itself, and not that Roddy had lost the plot in his reloading processes somewhere)
Winchester and Hornady brass are somewhere in between the Federal and the Highland for variation.
In my (limited) experience, I would prefer to buy new Lapua or Norma loaded cartridges, and reload them for ever and a day.
However, given thats pretty much impossible for me to do, if I need to buy loaded ammo, I try to buy OSA/Buffalo River ammo, and reload it as needed.
Along this line of reasoning, I have had excellent results with the factory Buffalo River 87gn V-Max .243 Win loads, and you can buy them in 480-round cans.
The projectiles are a bit heavier than what The OP wanted, but they fly well(BC is up at 0.4), hit REALLY hard, and you get decent brass to reload at the end.
A can of 480 rounds currently retails for around $655, which comes out around $1.364 a round, which isnt too bad for quality ammo.
Anyway; thats my experience.
Other suppliers (in Toowoomba area) are 'The Open Range'(Toowoomba), and 'The Barn'(Oakey). Both have online stores.
Cheers,
Rod.