Pricing of search engine optimization services is sometimes an area businesses find hard to understand. The truth of the matter is, there is not always a flat rate that can be applied. I feel flat rates can be given to sites wanting the basics of SEO, without ongoing work. And even then, the size of the website must be taken into consideration.
Generally, I would say, someone wanting ongoing search engine optimization techniques applied to their website would have choices of different packages offering the many different services needed to optimize their website. A lesser package would offer fewer services, a greater package would offer more aggressive optimization. Your best bet is to find an SEO Specialist, preferably by recommendation or reputation, and have a consult with them to work out a package that is affordable, as well as profitable to you.
I have noticed more and more that many SEO services and specialists are offering what they call “performance-based SEO”, meaning they are offering you to see results of their work before you pay them. I don’t think you can get better than that!
Of course, if none of the above appeals to you, there are definitely courses, both online and in person, where one can learn the basics and even the advanced SEO tactics. If you have someone that you hire to do your web work, you could send such person to a workshop, tax deductible, to learn the ropes. However, though you may be saving dollars from paying an SEO firm or specialist, you would maybe need to compensate such employee for the extra specialized work he would be doing as it is not normal web design or website creation activity. It is an animal in itself.