That looks like a currency discrepancy, as if there are two different currencies being factored in. (And, based on the current exchange rate, I'm guessing the second currency is the US dollar.) When you browsed as if you were a guest, where were you located? In Australia or elsewhere? Were you perhaps using a VPN that used a server in another country? What browser were you using?
When I view your listing (I'm in the US), your standard rate (the one in large type in the dark bar at the bottom right of the opening photo) is $435 (USD). When I open the calendar and mous over dates, the open dates in April show $395 (USD). Further out in the year I see your default $435 (USD). The April dates match (close enough) the $396 you mentioned, so this is more evidence that there's some currency discrepancy involved, either via your browser or at AirBnB (which I doubt).