Developer of Paper here. 
One of the users shared this thread in the feedback chat, and I figured I’d jump into the discussion.
As I mentioned in the linked article, I always experiment with pricing. This latest experiment is the most expensive yet. I am trying to find the limits. There is a big chance the experiment will fail and I will revert to smaller prices.
So far I can say that there are people who will pay $30/month and $100/year for Paper. And to me - these people are out of their minds! But if they see the value in what I’ve created, I would rather convince one person to pay 30 than 6 people to pay 5. It’s much easier.
What people often forget when they start comparing ultra-niche apps like Paper with the mainstream is that Paper is not 10 or 20 smaller than them. It’s more like 10000 smaller. The power dynamic between market leaders and the long tail is astronomical. So if they can make significant income on $1-10 lifetime, for Paper it makes much more sense to find a few super-fans who will pay 10x more. Believe me, I’ve tried all price points and pricing models. Lowering prices does not give you anything, because what matters is distribution - being on people’s minds, in the media articles, in video reviews, and search results. And yes, lower prices do increase word of mouth, but not enough to make a difference if you are a small, unknown developer from Eastern Europe that nobody will even know or care about.
Besides, for most mainstream users, features are what determines the value of an app. Hard, analytical facts of this vs that. But Paper is not like that. It plays in the field of emotions, feelings, and inspiration. You cannot use these qualities in a comparison in a review article, or convey them to a friend. They are personal. And I can say that over the years a lot of people have reached out to me saying that Paper is exactly what they were looking for after trying everything on the market. A few days ago someone wrote: “If Paper were to ever become unavailable, I’d probably spend quite some time crying.”. I don’t know what these people see in my app, but, for a ridiculously small % of the market, Paper sparks the right emotions, and makes their writing experience better. I want to serve those people.
And yes, as already mentioned in this thread, Paper has a pretty usable free version, unlike many competitors. The paid features come with the most “trialable”, zero-friction model on the market. I want to give as many users as possible the chance to experience the full version, so they can evaluate if it is right for them.
And yes again, I try various price points for various countries, with differences sometimes reaching 10x. I am always amazed by the purchasing power of the US.