T. A. Rodgers
Noizchild, only you can decide which direction you want to go with your novel. If you feel great about you work and feel it’s ready, then why not test the waters and query some agents. You may find great success. I would only recommend an editor for traditional publishing if you have written several novels, have been reading, studying, and learning the craft, and the comments from agents make you believe that the novel is almost there, but may have an issue that is preventing the noes from becoming yeses. Remember that you are spending money that you may never get back, although since you have already self-published, this route would only make the novel better.
I can not stress enough though that if you decide to hire a developmental editor please pick one that has verifiable evidence that they know what they are doing.
FYI: I plan on working with an editor very soon that I met at ThrillerFest via a senior editor at Houghton Mifflin Harcourt. I would not hire anyone else, but someone that comes highly recommended. And she won’t be cheap. It will be several months before I’m ready as I need to take the current novel and edit based on past recommendations from several agents, a few authors, and my friend at HMH. We shall see if it pays off. This is my 5th novel.