Around 2012-2013 (I think) I had an app where I had reverse engineered the Omnifocus sync protocol so you could "use Omnifocus" on an Android phone. After experimenting with pricing a bit I think I left it at $20 and consistently had a few sales per day for months. I have received zero complaints about the price. It was a simple one-off transaction for an app that solved one specific problem well.
It wasn't serious money but a nice addition to my salary at the time. I highly doubt a price point like this can still be done in the current app environment.
No, it could be done, if you could identify some little niche like that, and charge for it.
Imagine some lawyer website or whatever that lawyers have to login into and it's an absolute PITA on Android, but you make an app that does that part for them, charge $100, done. (Obviously this example doesn't work, but that kind of thing).
It wasn't serious money but a nice addition to my salary at the time. I highly doubt a price point like this can still be done in the current app environment.