I know you want to build a good journal, but may be limited by funds. [On the other hand, I could be wrong, since you only charge USD75 (not USD-75) for each paper.]

If you want to have a good journal, start it strong. You need to make sure the English is good. If you screen a manuscript before sending it off for review, which you should to respect your reviewers' time, I suggest that you make sure the English is readable. If not, ask the authors to seek editing service. You may provide a link to some editing companies, which I can help you.

When a manuscript is good enough to be accepted in terms of science, but not in English, you could offer assistance by hiring your own English editors, or tell the authors to do so on their own. I assume your journal or your publisher offers technical editing, which is very important in my opinion to make sure each paper appears as clean (professional) as possible.