There are two simple reasons you should hire a professional:
1) The work will be done right the first time.
I know you're smart and good at learning new things. You wouldn't need my services if you weren't. You and I both know that even quick learners have a learning curve, and that mistakes will be made along the way. Do you want to make them now, on this project?
2) You have better things to do.
Do you really want to spend hours fiddling with formatting and flipping through the index of the Chicago Manual of Style? Or would you rather work on your new research project, play with your kids, have lunch with your colleagues, or get some fresh air? Your time is valuable, and I'm efficient; hire me, and it will take less time—and that time won't come at the expense of the things you'd rather be doing.
So why not take a look at the services I offer, and see if any are right for you?