I obtained a traditional 3-book deal April, 2017. Before this, I had hired a developmental editor that taught me a lot about writing and helped me get to a professional level; if not for her, I wouldn't have gotten as good as I did. Now the dilemma is the following: my publisher provides free, quality editing for me as part of the contract. My old mentor is expensive, especially to an undergrad student like me. Should I still hire my old mentor even though I absorbed the lessons well (active voice vs. passive voice, showing vs. telling, sentence structure variation)? Or should I stick with my publisher's quality and free services?

I don't mean to sound arrogant - I'm simply stating an honest evaluation of my improvement and the opinion is shared by beta readers I have.