I've learned that professional book editing costs can vary wildly depending on the service and the editor's experience. For a basic proofread, you might pay around $0.01 to $0.03 per word, which translates to $500-$1,500 for a 50,000-word manuscript. Developmental editing, which digs deep into structure and content, can range from $0.05 to $0.10 per word, so $2,500-$5,000 for the same book.
Copyediting usually falls in the middle at $0.02-$0.05 per word. Keep in mind that specialized genres like technical or academic writing often cost more due to the additional expertise required. Some editors charge hourly rates ($30-$100/hour), which can be unpredictable, so per-word pricing is often preferred. Always request sample edits from multiple editors—quality and style fit matter just as much as price. Budget at least $1,000 for a solid edit, but don’t shy away from investing more if the book is complex or meant for commercial success.