I see that this is very similar to Paper by 53 in several aspects... Is that what you are trying to compete with? In that case, I wonder the logic of an upfront price instead of Paper's strategy which is to give you something to try out... At $4.99 a pop, it is much harder for someone to take the plunge.
I do take your point. In fact I'm in the process of writing a small update with In App Purchases. With this update, it'll be free.