«Better editors will command a higher cut; the best cover designer will have a waiting list. (publishingperspectives.com)
They don't shy away from having to make sure they find good editors and proofreaders, good cover designers, etc.. (madgeniusclub.com)
It's not only part of the book's production but should also be the strongest piece of marketing collateral you have, so hire the best cover designer for your book, not your budget. (editorialdepartment.com)