When you say "purchase a professionally written resume", it sounds like something generic that's been sold to anyone willing to pay the price.
I will pay to have my resume written by a professional. This will be my skills, knowledge, experience and strength, not some generic resume that's flying around on the web somewhere.
Professionally written resume definitely helps to convey all your years of experience, aquired skills to potential employers in a well organized and industry standard or format.
So I definitely want someone who is trained or schooled in the art of resume writing to help me put it together.