SEO is more complicated than ever with Google constantly updating their various algorithms. There are different algorithms for local search vs. organic and algorithms that penalize a business for poor backlinks or awards them for high quality backlinks (The Google Penguin Algorithm) and an algorithm that ranks a website based on the quality of it’s content (The Google Panda Algorithm). It’s no wonder that SEO rates have been increasing over the years.

Check out this survey that shows how prices have been increasing and what most agencies are charging:

http://www.websitemagazine.com/content/blogs/posts/archive/2016/10/11/seo-pricing-in-2017-understanding-the-average-cost-of-seo-services.aspx