Whenever people give specifications of what kind of website they want, the requirement is straightforward.
„I want a tiny, little, small website!”
The thing is, the end result is almost ever like this.
„Oh, but I also need this. Can we move things a bit? Can we make it more «lively»?” etc.
When you are billing for a project, take into account that the initial specifications and the end result might differ.
I tend to bill web development projects by the hour, not by the project, based on the fact that there tends to be a difference between „initial specifications” and „end result”.