I am a freelance fiction editor, based in East Hampshire, UK, successfully running my own business since 2012. I am currently only undertaking editing projects for previous clients, but am happy to offer advice to independent authors wishing to self-publish or submit a manuscript for publication, and who would like to know more about the editorial process.
Professional editing is not a quick fix of spelling, grammar, and punctuation; neither is it to read through a story to see if it has merit. It is a skilled job of presenting the author's words, intentions, and meanings to the reader; in a clear, concise, and coherent manner. With this in mind, it is important for the independent author to realise that the journey to publication is a long-term project.
This website contains a lot of information about the editing process and all the stages through to self-publication. If you are seriously considering either, I recommend a read through so that you have a basic understanding of what is involved. Writing the story is only the first leg of the journey. Yes, professional editing costs money, but it is a financial investment that will set your novel apart from those that have not benefited from such a service.