Some authors budget very unrealistically, perhaps just a couple hundred dollars. (I’m not saying this is necessarily true in your case, but I have encountered it.) In such cases, I find myself wondering whom they are imagining should bridge the gap between what they are comfortable paying and what the editor needs to earn in order to pay expenses and support him- or herself.
Just launched my new novel "Who is Waldo Wiggins?" this past weekend and the response has been great. Ebook Launch did all the cover art (front and back) for the paperback and ebook, and they knocked it out of the park. The first thing people mention is the cover art and the great job that was done on it. Personally, I couldn't be happier. The end result was beyond my expectations.
That’s a great point about other disciplines. Why should writing require some outside arbiter? Is it because these other disciplines consist in crafts that require significant training, whereas anyone who’s literate can start writing a book at any time (and therefore, the threshold for entering the medium is much lower)? I do hope you’re right about learning self-editing skills. I actually just made a YouTube video about how to self-edit: https://www.youtube.com/watch?v=3mmLEuH9x28
As for multitasking, believe it or not, I try to schedule so that I am only working actively on one book at a time. Research keeps showing that “multitasking” is actually less efficient, because of the time lost to leaving behind one task to restart another. (Think of it this way: If you take on two clients at once for work that would take one week each with your full attention, either you can tell both clients the work will be done in three weeks because you’ll be alternating between them, or tell one client it will be done in one week and one that it will be done in two weeks, because you’ll complete one before you start on the other. Which of those makes more sense?) Obviously, with back-and-forth communications, sometimes complete “monotasking” is impossible, but I think it should be considered the ideal.