UNITY: Features – iPhone Publishing is nice for indie developers that want to get into some iPhone game development and have a background in C# or javascript. A lot of 3D engine/physics already taken care of for you. They have a nice community that is very helpful.
Your first game can cover the cost easily.
I use it along with the iPhone SDK for my game development. A lot of people don't even touchthe iPhone SDK when they use Unity, but my game uses a lot of GUI menus and stuff, which the iPhone SDK is a lot better for.
