For the second time in as many months, a new customer has said to me something along the lines of:
"You weren't the cheapest option, but I guess good work costs."
In reality I suspect that there are two ways of getting a good edit: for free, or by paying what the job is really worth.
You can get a good edit for free. Generally speaking, when someone does you a favour, they do it conscientiously. (Is that really naive of me? I hope not.) I'd be inclined to suppose, though I admit on no evidence, that this is more true for a copy edit than for a literary* edit.
If you pay someone for an edit, there is a very simple way to work out if you are paying enough.
(1) In the USA, the minimum wage is $ 7.25 an hour. If someone quotes you $ 200 for an edit of your 75,000 word book,
(2) that's a total of 27 and a half hours or 2,727 words per hour.
(3) That sort of speed is perfectly "possible".
For a writer who is experienced and reasonably competent at narration, I won't need to make notes more than once every few pages - and mostly on story and characterization at that rate, I can read and take notes at more than 5,000 words an hour. If the writer is less experienced, or makes lots of errors or there are generalized narrative or stylistic problems, my speed can be cut down to about 2,000 words per hour. This is excluding time that I take to think (anything up to 2 days for a book of that length), the time taken to organize, structure and write up my notes (1 to 2 days) and time spent discussing all this with the writer (2 to 6 hours, though sometimes as much as 25 hours; I don't count this however as writers' needs can vary so much).
So for an 75,000 word book with average problems, I would need just over 40 hours. I base my prices on my estimate of the amount of time a book will take me, because it does vary a very great deal.
Going back to (1) above, if you paid me at the same rate as someone flipping burgers, I'd still need $ 293. But you ought to expect to hire an editor with qualifications and experience that are more difficult to acquire than those needed for flipping burgers, and such people are not all that easy to find. In short, someone who is going to help you to add value to your work is going to cost more than the minimum wage.
In my case, my lowest rate would, based on the figures above, be about $ 28 an hour. Someone charging you $ 200 dollars at that rate would have to work at a rate of 10,500 words per hour! That sort of speed is not possible.
In my opinion, there shouldn't be much difference in cost between a copy-edit and a literary edit. The skills, knowledge and experience required may overlap, but they aren't different degrees of the same service. They are different services provided by different specialists (many editors offer both, and I assume in my usual naive way that that means that many editors are equally or nearly equally good at both; I am not). In both, you require a degree of specialist knowledge, thoroughness and attention to detail that is relatively uncommon.
Ultimately, you should pay what you can reasonably afford, and of course, you get what you pay for. What I hope to have done with the above is show that you can, to some extent, work out if you are being charged too little. This is only possible because you know that the job requires both time and undivided attention.
I don't think there's any meaningful way to judge if you've been charged too much based purely on the price. You have to see the completed edit before you can tell.
* yes, I'm still using this term as an umbrella for story development, content editing and writer mentoring.