I could do it for free (I put the minimum to get in contact with you). If I'm not mistaken, your mother tongue is Spanish, isn't it? Send me your article, and I will give you my corrections. If you are satisfied, we could continue working together or you could recommend me. You get your piece of writing corrected and improved, as for me, I get some experience in the freelance world. Win-win situation, right?
To be honest, I'm not an English native speaker, but I''m in my last semester of Modern Languages with a specialization in Linguistics and Literary Research; therefore, I'm able to write and do research at a university level (essays, summaries, reviews, research proposals, reaction papers and among others). Indeed, next July I'll be writing my thesis as a requirement for my graduation. Anyhow, too much talk. I could continue talking about it, but what matters is the end result.
By the way, I would like to know more details about the research task in order to help you better with that.