I write material that portrays the value. I also write detailed patents, grants, business plans, and application notes. The more detail (patent) and knowledge (engineering and grants), the higher the rate. Rates are lower for areas that I don't have to research heavily such as basic electronics and automotive knowledge. Note that I am a full time freelancer that can prioritize your project unlike others who get to it when they can after their career. This is not a side gig for me, it is a serious business. Check out my full list of services at: http://www.effective-technical-writing.com/