The cost of editing services depends on a variety of factors, including the length of the document, the type of editing, the speed at which you need the editing completed, and the level of expertise of the editor. The best way to get a ballpark estimate is to contact a few different editors and request a quote. Make sure you let each editor know what you're looking for, including turnaround time, document length, and the level of editing you need. Once you have a few quotes, you can make an informed decision about which editor works best for you.
