In fairness to duolingo, nearly everything duolingo does is like this. They are extremely metric and process driven (for better and worse of actual users).
For reference it is 10$ CAD per month or the Family option which is 12.50 CAD per month.
I assume they do regional price adjustments though.
I think it's an example where metrics are taken too far. Yes, better DAU is good, but if you are alienating 100% of your power users and getting more engagement from your short-term, new signup users that's going to look great for a few quarters but kill your app over the long term as the community experts start telling everyone they used to recommend Duolingo to to go use something else.