I hope you consider an open source model: code available freely on GitHub & app available for purchase on your website.
I was scared about doing it this way, but it worked out for me: https://videohubapp.com/ for pay-what-you-want-$5-minimum for my app, and https://github.com/whyboris/Video-Hub-App git-clone-and-build for the code. I currently sell about 60 copies per month (same average across the last 4 years too).
I've not kept statistics, especially that when people purchase they get access to all the OS versions. I'm guessing it's over 50% Windows but Mac is no less than 20% of the purchases. I don't sell my app through the Apple App store - it's just whoever stumbles across my website (I've shared it on Reddit a bunch of times over the years, but not aggressively). I think I mostly got lucky with naming - where "video hub" is close to "porn hub" and people find it unintentionally :)
I was scared about doing it this way, but it worked out for me: https://videohubapp.com/ for pay-what-you-want-$5-minimum for my app, and https://github.com/whyboris/Video-Hub-App git-clone-and-build for the code. I currently sell about 60 copies per month (same average across the last 4 years too).