iPhone 5S: Screen Protector

I have a screen protector on my 4S, but now it's come to the point that its always smudgy and doesn't stay clear even after I clean it with a cloth.

I, however, don't have a screen protector on my iPad 2, and I love the feel of the screen. But my iPad is always at home, and safe from scratches. But my iPhone obviously is not.

So I'm getting a 5S soon, and am not sure whether I should get a screen protector or not. I don't want it to get all smudgy.

I wanted to hear from current iPhone users and whether or not any of you have a screen protectors. Plus, if the screen gets scratched, how much is it to replace it?

Thanks