Which mobile OS’s apps make most money? Surprise! It’s BlackBerry
Economics 101 - First Lesson: Supply and Demand.
That’s what happens when there is no competition: producers (e.g. app devs) can charge more.
The obvious downsides are the lower potential number of sales/app and the fact that it won’t last long. Does RIM have more than a year left in it? I doubt it can limp on for two…