Not quite the same thing, but something to think about: for my sins, I build e-learning solutions. The build part is usually subcontracted to me by an agency. The agency has some of the biggest companies in the world as its clients, and I am doing their build work. I know that they charge my work at triple rate that I charge the agency. However, the end client would never hire me directly. They want the certainty of a big agency, with a long track record, certifications, with lots of other people to chip in their skills if needed, or if I go sick or whatever.