I am the freelance consultant. you can Hire my service to requirement gathering and specification before going to a vendor to get a solution.
I will help you to identify the key area of required solution and can help you to deter mine the eforts required so that if you will hire any company for the solution, they will not be able to have disadvantage by knowing that you are less technical in terms of web development.
My Requirement gathering charges are $20 per page.
1 page DFD $50 extra pages each of $30