This looks like an inventory clearance price for Model Y MY2024 manufactured around August to September 2024.
It's $2,000 further cheaper than previous $53,300 inventory discount price from initial inventory sale https://www.ozbargain.com.au/node/888355.
Stock only available in WA and there is $350 discount if you use a referral link.
Besides, WA ZEV Rebate for $3,500 (apply separately after you get a qualified vehicle) available until 10th of May 2025. It is like refund stamp duty for the EV registration.
Save further if you can get novated lease on it as it does not attract any FBT.
By a Tesla if you want it vandalised