You never asked me how I did my audits.
Aside from the basics (checking tags, metas, page speed, technical issues etc) I tear apart the site to make sure that each page is targeting one keyword, and that each keyword is mainly triggering one page (basically making a keyword-content map). If they have two pages targeting the same keyword, or if one keyword is trigering two different pages (assuming only one page at a time is on the first page and they don't have both ranking on the first page at the same time), I'll give recommendations on how to de-optimize one and optimize the other so Google will start reliably serving up the page my client wants seen for that keyword.
Then we drill down into the analytics and see if there is anything creating friction to get the user from the page they landed on to a conversion point.
I'll do gap analyses to see if there are any keywords or backlinks that my client's competitors are targeting that they aren't, and which ones would be the easiest to target/acquire.
I also examine interlinking to make sure the site is architected in a logical and efficient way for Google as well as users to navigate around the site, while also providing Google with enough signals to show them which pages are the most important.
I do a quick reputation check to see if there is any negative press or negative sentiment about the company and brand floating around online. One time I had a client who was being slandered as a being Russian bot on Reddit and they had no idea.
Once that is all done, I'll take their targeted keywords that are stuck on the 2nd-4th pages and run a correlation analysis to see where they are falling short and what on-page changes they can make to give them the best chance of getting to the first page. Usually once these changes are implemented the desired page is ranking on spots 4-6 without any additional backlinks being built within a few weeks.
Then I wrap it all up with a video meeting where I go over the report, answer any questions they may have, and help them build a roadmap on how to fix any inefficiencies on their site and optimize it going forward.
Depending on the size of the site, it could take me anywhere from a couple weeks to a month and a half.
Edit: I'm not just charging for the work itself being done. I'm charging for all the years of experience I have. Think of it this way. I'm charging $10 for the work, $1990 for knowing what it all means.