An inexpensive editor is usually not worth the money. And I don't know if you mean developmental editor or editor you want to submit to at a publisher. You should know large publishers only take submissions from agents.
This is the sort of research you have to do. How you go about getting a manuscript traditionally published depends heavily on your genre. There are dozens of agents for most genres. Each has very specific preferences. It took me 2 or 3 months to build a list of 50 agents to query (based on what they want and if they're reputable and currently selling anything). Personalizing for each agent's submission requirements and preferences takes about an hour per request. That's research only you can do. Only you know your book.
Depends what type of publisher you're looking for. I have two books that were published by academic presses and I didn't hire any editors before submitting it. Although, I did have a few experts read the manuscript early on.