Aussie HiFi Market

I'm trying to gain some insight into the Australian HiFi market from a buyer's perspective, namely:

Used Gear: How is used gear traded in AUS? Is there an online platform specific to AUS or are Aussies using the same platforms as the US e.g. Agon, US/Canuck Audio Mart? If latter, how was your experience importing gear from North America including any info on tax, duties, tariffs?

Go To Retailers: Who are the knowledgeable and trusted retailers of high end HiFi gear? Is it typical to ask for a discount on expensive gear or is it culturally not a thing in AUS

Aussie Brands: Any made in Australia brands you would highly recommend?

Cables: Do companies like Nordost or Kubala Sosna make Australian power cables or are people using US/UK cables with adapters or power distributors?

Aussie HiFi Clubs and Associations: Any local HiFi club, association, newsletter, forum you would recommend?

Other: Any other advice or pointers are highly appreciated 

Clearly by now all Aussies reading this will know I'm not from Australia so please excuse my ignorance of your market. Many thanks