I've got a dev team of ten, working mostly on iOS and android game apps for hire. We've done 8 iOS/android games in the last couple years, some of them AAA, some not.

Paid ($1) games of a decent quality typically generate sales between 40 and 100 thousand; and can do much better if 'everything goes right'. Development costs are roughly the same. For apps, seems around 75% of cost is on the engineering side. Design is all from third parties here but included in the above figures.

Work is enjoyable.