I'm not quite clear exactly what the task is but I am experienced in all of the areas you mention. Before accepting the proposal I would need to know exactly what you require. Your problem, it seems, is that there is too much detailed and time-consuming work to do while I have spare time and an solve this problem for you accurately on-time, every time.
I have taught computing in schools for 12 years, including the use of Excel for data-processing and web -searching. In writing I have successfully written copy for my own business and have written for many purposes - educational texts, copy-writing and web-content for my own business and even plays. This should assure you of the skills that I will use on your behalf.
I would certainly like to know the details of what you are planning. $5 per assignment sounds fair based on what you say but please do get in touch to let clarify what the task is.
Thank you
Frank