Your $5.99 isn't enough to support developing anything but a cheap, top-50 hit of an application. Thanks to remarkably steep price competition and remarkably poor discoverability, the app store very much lacks anything resembling a long tail.

We sold a small app for $1.99, just to compete with similar apps in the space. If we'd sold our app for $5.99, we would have made a tidy profit on solid initial sales and moved on to make another application. However, at the $5.99 range we're competing with much more polished and comprehensive applications. This left us barely covering our development costs at the $1.99 price, with our sales rapidly declining after the first month.