The link is to the Australian eShop, where the game is currently $43.95.
42 Gold Points is about 1/5th of what was needed for the last such price error for the Blasphemous 1+2 bundle, which was 205 points.
Claiming the Metroid Prime Remastered cart in the Agentina eShop last time got me 308 points. The amount of points you get from different games can fluctuate a lot, but I expect any game you can redeem will probably give you far more than 42 points.
Copying and pasting my recommended process:
1) Create a new Nintendo account
2) Put in all the necessary details to create an account, setting your "Country/region of residence" to Argentina.
3) On your Switch, go to System Settings > User > Add User > Create New User, then you should be able to link the accounts.
4) You may have to log into the eShop at least once with the new user profile, just to make sure the new account recognises your Switch as the primary device.
5) Insert a game cart to your Switch, press the + button, scroll down to the My Nintendo Rewards Programme > Earn Gold Points, then choose the new user profile for the points to go to.
6) When you try to buy the game, it should give you the option to use Gold Points to reduce the price. In this case, 42 Gold Points brings it down to $0.00.Some things to be aware of:
- Gold Points can only be earned this way on physical game cards. (On digital, it's always against the account that made the purchase.)
- Gold Points can normally only be earned within a single year after the game's release. (For physical game cards.)
- The chances are not zero, but if you've neglected to redeem the points of games that are already over a year old, you're probably out of luck.
- Once they've been earned, the Gold Points will expire on the last day of the month 12 months later.
Here's the page to check if you have expiring Gold Points on your account: https://my.nintendo.com/point/expiration
Confirmed working (the game is currently downloading on my Switch) as at the time that I hit "Submit" on this post.
EDIT:
Advance Wars 1+2, which I got for $40 (through this deal + $10 Target newsletter sign-up) offered 231 gold points from the Argentina eShop… Meanwhile, it offered 80 gold points (worth $0.80) in the Australian eShop.
Based on that metric, this price error is equivalent to getting the game for around $0.15.
Got it. Thanks OP.