It’s difficult to provide a specific fee, as every author’s work is different, and every editing job is different. While my standard, corporate, rate is $60AUD per hour, I offer generous discounts for individual authors, students and community-based organisations (usually I don’t charge for community work).
When approached by an author, I ask them to send me three extracts from their work, from beginning, middle and end. Based on that sample, I work out whether I am able to help them, and also do an estimate of the time it will take for me to do the job, based on an hourly rate.
If it is a longer work, such as a book, I work in instalments so the author doesn’t have to pay the whole amount in one go. It also allows us to review the work as we go along.