In traditional book publishing every author has an editor, however in the self-publishing industry the area is a little grey.
Of course it would be fabulous to have the input of an experienced professional but costs can be prohibitive. One one hand you've slaved away for many months to create your book, but do you then spend a few hundred pounds on editing services? While you may want your story to be the best it can, costs may be out of your reach.
I faced this dilemma recently on the first in my series of cozy mysteries featuring gardener Natasha Green. I've worked in the newspaper industry for many years, both writing and editing articles. I like to think my grasp of grammar is reasonable but wondered if my story lacked professional polish.
As the story was under 11,000 words, the cost wasn't excessive (under £55) so I decided to treat myself and see what an editor would bring to my novel.
When it was returned I was happy to see that there weren't massive red lines all over it and the plot and pacing held up to scrutiny. The line edits showed some areas of dialogue and description that needed tightening up and the feedback gave me a couple of points to work on. Most of all it gave me reassurance my self-editing was fine.
Overall I was pleased with the result and wouldn't rule out doing this again for a short story, but I'm not sure I'd be willing to invest my hard-earned cash on a longer and therefore more expensive novel. At least, not until I'd built up some sort of following so I'd know there would be a few sales to make up costs.
I'm lucky to have several years of self-editing experience but if you don't have that the good news is there are lots of people out there willing to help authors who wish to self publish. I'm talking about Goodreads.
While most editors charge a fee (or you may find a low-cost service on Goodreads) there is also the option of beta readers, some of which will give their time for free and some will also offer light editing as part of that.
Beta readers will look over your novel from a readers point of view and comment on characters, plot and setting. While they are not editors you'll get a good insight into what does and doesn't work in your novel. Most authors tend to have beta readers look over their work before it goes to an editor, but you could do the process of re-writes and beta reads a couple of times to knock your novel into shape.
One thing that does need to be right is spelling and grammar and this is where proofreaders come in. Most will charge but they are cheaper than editors so this may be within your price range.
Otherwise get searching within Goodreads groups for some worthy volunteers.
So the questions of whether to use an editor or not? I'd say yes, every book needs an editor, however not every author can afford one so beta reading and proofreading are good alternatives.