If you are interested in how much you should pay for SEO it may be useful to analyse SEO companies, their structure and their techniques. Perhaps the techniques they use to market to you are interesting as well.
The short Instructional Video is more tolerant of unpredictable things that occur while recording and it is a chance for the Presenter to reveal their unique personality, energy, humour, knowledge and enthusiasm for their subject to their viewers.
There are pros and cons in any system. As an SEO I have even had success with basic builder systems that come with cheap hosting accounts. Google allows a massive degree of tolerance. The take home from this is, you are going to need an experienced web developer no matter what system you use.
A small business may simply have a website, and handle enquiries on a case by case basis. These enquiries may come via a phone call or a simple form on the website.
How well your website and SEO is integrated into your business can severely affect your growth opportunities.