Editors Should be Respected.

There is nothing more tedious that having to go through your own work while attempting to divorce yourself from the tone, knowledge, or vision you have of that book. You have to find everything you've done wrong, which is guaranteed to be a lot, and then figure out how to fix it. A passing friend can only do so much, assuming they're willing to be as harsh enough about your grammar and narrative flubs as to be useful.

The people who do this for a living absolutely are worth what they're paid.