I would be able to complete this project within a day of being accepted. I have plenty of experience writing articles and have managed to sell them on other sites for $20 or more. However, on freelancer, I usually sell them for $2-$5 because no one here pays more. So I can work for whatever price you are offering.
Let me know if you need examples of my work, I would be more than happy to send you some. I may even start on an article later today if I have time (if you don't want it, I can do a quick edit and sell it as "The Benefits of Running"), but I have a few other projects to get done first.