Ultimately, this is a question only you can answer. However, I’ve listed a few things you may want to consider as you decide whether or not to hire someone before publishing.
1. You’re a professional
If your goal is to be a professional writer, please consider the quality of the work you’re putting out. Does your unedited or self-edited manuscript scream amateur. If you put out something amateurish it could have a negative impact on your long-term career. If you think your work is at a professional level, get a few unbiased readers to have a look at the first few chapters.
2. You’re a new writer
You haven’t published anything yet and you need some advice to get your manuscript to a commercially viable level. Great, if you’re recognizing that you need help, it’s time to decide what type of help you need. Head over to my services page to get an idea of the options available.
3. You are not perfect
This is the most important point. You are not perfect. Even professional editors use an editor to get their writing ready for publication. What makes you think you are better at editing your own work than they are?