@NatureMC Human editors are much more expensive, and do a much wider range of tasks. I'd say WordRake is only really good for catching some grammatical errors (and not even all of those). I'm not sure what you're using it for (and how often) but all editing takes either time/money and usually both.
@susankayequinn @NatureMC Maybe you can check out LanguageTool which is open-source and you can selfhost as well:
https://github.com/languagetool-org/languagetool