How can I keep costs down and still work with a professional editor?

You have some control over the prices that you are offered for editing services.

Here are some ways to lower costs:

Start Early

Start your search for an editor before your project is done. Ask editors when they are available and how long the editing will take. Factor that time into your personal deadline. Be sure to leave time at the end of the project for you to review their edits.
Finish your project far enough in advance of your deadline to avoid rush fees.

Many editors base their fees on word count, even if they offer you project pricing. Reduce the word count or page count of long projects as much as possible before submitting to lower your project cost.
Not sure which sections can be cut from your book-length project? Paying for a manuscript evaluation or developmental edit might be a good investment. Choose an editor familiar with your genre so they can advise on you the industry-standard length for the type of book that you’re writing.

Editing services that use a team of interchangeable freelancers can often get someone started on your project right away. They also appear to be cheaper. However, you may end up paying a rate that’s too high for the quality of work you receive. Why? Your editor won’t be able to talk to you about your project or look at your document to evaluate the services needed. This may mean there is a mismatch between the pricing you’re offered and the work actually needed. These services also take a portion of your editing fee, and give only part of it to your editor. Low rates and lack of personal connection to the client create an incentive for the freelancer to do the job as quickly as possible. They may stop working on your document when they are out of billable hours at a reasonable wage, not when the job is actually done well.