Seen that someone had posted this for Aussie eshop 33% discount $40.16, however, the price has now been updated on the Canadian eshop and works out significantly cheaper.
$26.79 CAD + 5% VAT = $28.13 CAD ~ $28.10 AUD
Make sure to set up a separate Canadian Nintendo Switch Region Account
with the time zone: (UTC-06:00) America/Edmonton for the lowest sales Tax Alberta 5%
If you want to avoid International Transactions fees on converting to CAD you can Buy Candian e-shop codes in AUD from PCgamesupply + Instant delivery
Edit: It seems international cards where blocked a few months ago via zip code checking, this essentially leaves the codes as the only option.
Worth mentioning, if you change the region of your account and add eshop credit, you cannot revert for so long as you have a positive balance.
Don't add $30CAD, buy the game, and hope to change back to Aus.
With that in mind, does a 28 Degrees card work with the Canadian eshop? I had no luck when trying to use it with South African one.