Forget all that! White plastic bag and a rubberband works for me when I can't bounce the flash!
That's a great idea, particularly if you're getting good results. It could save the day! I'll put a white plastic bag and rubberband in my camera bag.
If you're shooting for a client, there is the often overlooked matter of perception. Photographers are expensive people to hire. Regardless of the results you can achieve with a white plastic bag, clients don't want to see that. They want to see you with a camera and lens combination that they either can't afford or justify, and accessories that suggest innovation and professionalism.
Assuming you have the required personal, ethical, business, creative and technical abilities, the way to make money from photography is to be reassuringly expensive, and that means turning up with shiny new equipment, nicely dressed and in a decent car. On one level it's total BS, but on another it's complete reality.