Possibly pricing error. It's rare to have such price on Switch. Be quick to change your region to US and buy it on your Switch. Enjoy!
For AU eshop its price is still $49.75 (Usually $99.95)
This is my first time post. Thanks to all OZ bargainers.
PS: I didn't expect that you guys facing so much problems. Your account should not have any pending credits when you are about to change your region. Or maybe you can create a new US Nintendo account. (I have three accounts AU, US and JP).
For the payment, My credit card which was opened in China can pay all the currency in eShop with no issue. (I used to change my region to even Mexico and Russia in order to buy some games with much lower price)
For the address and postcode used in US eShop, I used Alaska 99833, and you can have a try.