LTWW;
Disclaimer: The following comments and opinions are those of One person, who has had published One work of fiction. Having said that, this mystery novel took 4 yrs to write/rewrite, 2 yrs to shop it around, and another 2 yrs to refine/finalize, once a pub house was acquired. So, I have had a bit of experience...

Since your previous professions and background indicate a heavy skill-set with writing, written and spoken English language skills, etc., it seems you already possess the ability to QC your own work, that is, to make sure it is grammatically correct, punctuated correctly, etc. However, the type of editing that is the removal of superfluous words, redundancy, reduction/elimination of adjectives, condensation/consolidation/cuts, etc., is usually something a new author doesn't have experience with. (Ha! previous sentence is improperly constructed :), but then, I'm a fiction writer, so it just doesn't matter!) So, I guess it depends on what kind of editing you're looking to have done to your work. I know that my one humble little fiction book was worked and reworked and reworked, by me, quite successfully (Rev F was the final). As it happens, I'm a technical writer by profession, so I'm pretty good with QC editing, and over the course of numerous revisions, was able to develop a cold-blooded-ness about slashing words. By the time the manuscript got to a real editor at a real publisher, the only type of editing it needed was the aforementioned "cut and consolidate" type. Otherwise, I don't think they'd have been interested. That type of editing (cut/consolidate) was done very well by the Editor at the publication house and was part of what they did for me. So, perhaps you'd be OK with letting the iUniverse person cover that aspect (while you handle the QC aspect), saving yourself a lot of $$.

However, if you aren't quite confident enough in your own QCing skills, and the money you pay out isn't a big issue for you, and you do choose to go the route of finding a professional editor, the key is to research that branch of the biz, and check out Writer Beware and other writer alert-type websites to weed out the predators and bad apples (lots of them out there). An Editor that is going to charge big bucks would surely have several high level references, other clients, etc., to help ease your mind. Otherwise, I'd say you could easily be getting ripped off. Jeff Herman puts out an excellent Writer's Market type book. He lays it on the line about the scam artists, sharks and bloodsuckers out there. Might be worth the $30 or so, to get his book, and read up on his 'bewares' and other insights. I know I learned ALOT about the business, from that particular Writer's Market book.

In case of any interest, (I Had to get in a plug, after all...) my book is CHANCEY DOUBLE-BACK, a work of inspirational fiction (murder mystery/family saga type). You can read sample chapters on my website, (hyperlink in my signature), or go to Amazon.com, Christian Book Distributors.com, B&N.com, etc. It contains no profanity, or sex, and has only 2 scenes of very mild violence.

Good luck with your project. I hope at least a couple of my comments may have given you food for thought. I'll be interested to hear what you do, and what happens.