The App's I put up are more tools for the folks I work with, so while I don't expect to be able to retire on the money made, I at least hope it will offset the cost in being a developer for apple iOS, something I have been forced in to by the sheer number of folks that have apple iPhones, so for the iOS versions I am charging a small amount, for the android versions they are free - a one time fee to google of $25 is nothing compared to the $99 per year for apple, plus having to purchase at least two types of iOS devices so I can see how they look on them, stuff that looks nice on an iPhone looks a little rubbish on an iPad.
I think if you are in it to make a fortune, then yes, you really need a stand out product, its very hard in this saturated market finding something that is original enough to be the next angry birds!