Yes and no. Editing costs the publisher time and money. Publishers are not going to put a lot of time and money into a manuscript unless they expect to get a lot of money out of it. Many publishers receive more submissions per year than they actually have time to read. Whenever you submit, you want to put your very best foot forward. A manuscript full of typos and poorly punctuated sentences may, inadvertently, say to the acquisitions editor: "I'm going to be a lot more work than I'm worth."
The wonderful thing about self-publishing is that all the profit from a book goes into the author's pocket. The horrible thing about self-publishing is that all the expenses for a book come out of the author's pocket. If you want to compete with professionally published books, you will need to hire professionals (or become one yourself): this may include a designer, a cover artist, and an editor.
When you're in a bind, another pair of eyes can be a good idea. But even a friend who is good at catching typos cannot give you the same help and advice that a professional editor can. A good editor won't just add in commas and catch misspellings; they will help you develop the best manuscript possible and make sure you meet publishing industry standards. Depending on the type of editing you want, this may mean making sure you've used dashes correctly, changing "just desserts" to "just deserts" (unless you intended to make a pun), reformatting citations, or explaining that your ending doesn't match the tone of the rest of your manuscript—whatever the author needs. A good editor will work closely with the author, making sure the author's vision shines through.
No manuscript is perfect (it's very hard to catch your own mistakes), but you may be almost ready for publication. Contact me for a free sample edit and honest evaluation.
See the Services page for a breakdown of the types of editing I offer and differences between them.