I think the pricing is better here.. Or US if you are going... And remember warranty etc..
But.. depending on what you want.. I will answer the op.
When I lived there, best pricing I could find was
http://www.d-d-photographics.com.au. It is a bit out of the way in North Sydney. You can look online to compare before you go.
For high turnover consumer grade stuff: dare I say it: Harvey Norman - they price match so often have discounts to cheapest competitor.. Or go in with your advertisement from another storefront.. Not online shops. Purchase from them is really opportunistic.. Based on sale prices.
Other camera stores that I know are
Teds teds.com.au.
Digital camera warehouse.
http://www.digitalcamerawarehouse.com.au
Camera warehouse
https://www.camera-warehouse.com.au/
I never had any luck at George's, though it use to be good 40y ago, nor CameraHouse.
Bear in mind I have been out of Sydney for 10y so things may have changed...
Hope that helps..