Do I need an editor? And if so, how much does it cost?

Yes, an editor is crucial for ensuring your manuscript is polished and error-free. Editing costs vary depending on the quality of your writing, the type of editing needed (developmental, structural, copy, or line editing) and the extent of editing needed. For a good editor, prices it can range from a few hundred to several thousand pounds.  
 
Once the editing phase is completed, you will then need a proofreader.