Rates – Most online book editors are freelance editors, which means they set their own rates. Editors may charge per word, hour, or project. Editing is a valuable investment in your book as a good editor can turn your story from meh to amazing! But the highest rates don’t necessarily mean the best editor, and the lowest rates could be wasted money. Definitely take rates into consideration, but don’t select an editor solely on price.
Obviously there is a big difference. I actually started with screenplays (with some mild success) partly due to hearing that as long as you have a good story, the grammatical errors won’t be a big deal. Well, that was not true. Maybe if a producer liked the story or I was already established but every contest I entered always came back with feedback about the grammatical errors. Even if I won or placed as a finalist, I always received critique on that. Very little is spelling error, it was more about structure, etc.