If you're in the market for an editor, here are a few reasonably-priced professionals that have come to my attention.
Of course editing and proofreading are optional for the self-publishing author, but then purchasing your book is optional for the book buyer.
Derek Prior of Homunculus Editing Services
Hazard Editing Services
Red Adept Editing Services
Lyn Worthen @ Camden Park Press
edited to add:
If anybody else has any names, feel free to include them in the comments section. I'd love to hear about them.