I think a lot of people already know this, but I've just come across it. Only works on desktop as far as I know.

When an agent lists a property on realestate.com.au, they must also include a "marketing price range" so the property appears in relevant search results. The actual price as indicated on the listing can be whatever the agent wants.

Here's an example; https://www.realestate.com.au/property-house-qld-paddington-136998246

The above property doesn't show a price. It only says "for sale". Using Chrome, right click anywhere on the listing page and select "View page source". This will open a new tab with the listing's HTML. Crtl+f for "marketing_price_range" and you can see that the price range is 1.5m - 2m.

I've copied the relevant line of code from the page.

{\"listing_id\":\"136998246\",\"agency_id\":\"KXMTTJ\",\"marketing_price_range\":\"1.5m_2m\",\"price\":\"FOR SALE\"

Have fun!