SEO marketing can be free or not. You don’t have to pay search engines to show up higher in their results for certain keywords. At the same time, you don’t need to pay if someone clicks on your website from search results. From this point of view, SEO is free and won’t cost you anything.
However, these are only the benefits associated with SEO. While anyone can learn the concepts of SEO and how to optimize websites, it takes experience to make things happen and gain benefits out of it. Hiring a professional should be a priority for business owners.