I suspect it's all about whether your game is mainstream or niche. The latter probably will earn more with a slightly higher price point. It won't achieve mainstream success anyway, and you also do not have to worry about scaring the dedicated core audience away.
Cogmind is a good example of this[0]. Traditional roguelikes are typically in the "completely free" category. But that core audience that loves the genre is a lot more likely to pay twenty dollars for such an extremely polished and well-crafted game in this genre.
EDIT: Of course, whether or not clicker games are niche games with a hard core audience is highly questionable. If anything they are surprise addictions for casual players browsing the web.
Cogmind is a good example of this[0]. Traditional roguelikes are typically in the "completely free" category. But that core audience that loves the genre is a lot more likely to pay twenty dollars for such an extremely polished and well-crafted game in this genre.
EDIT: Of course, whether or not clicker games are niche games with a hard core audience is highly questionable. If anything they are surprise addictions for casual players browsing the web.
[0] http://www.gridsagegames.com/cogmind/