I think editors are worth it, particularly if you have the money or can work out a trade. As an editor, I personally love helping people realize the best version of their story. I enjoy the collaborative process and contributing to someone's success. As a writer, I've been pushed by editors and found the end result better than what my story had been before the editor. This can largely depend on the editor(s) you work with.
If you're the sort of person who really enjoys collaboration and you have the resources, I'd highly recommend working with an editor. I've done some gigs on trade (typically trade for art) and some paid (usually depending on the size of the project per week), and I know a lot of writer/editors work in a similar fashion.
On the other hand, if you feel most confident when allowed to brew something up on your own, no other voices to confuse the mad vision you have for your idea -- and I know some folks who really do work best that way -- then that's okay too. The downside to any collaboration is that you might not work well with someone, which can be frustrating.
And so a third option is to try a smaller project (before committing to something bigger in scope) with someone that you're interested in developing a potential collaborative relationship with. I do a lot of short comics for that reason, and it's a great way to get to know new people and see how well you work together!