Perhaps the tone (sarcasm?) of your post caused some downvotes, but your point is well taken. I didn't consider that the panels are not made in Australia. They are very likely made in China. I guess that Australia has much lower tariffs to import solar panels compared to the US.
From my Internet goggles, it seems like home solar panels is common for single family homes in Aus. It might also be that installation is more competitive, thus cheaper. Or planning and fees are lower.