I used to be billed out at $325/hour as a junior programmer and it wasn't until later that I fully understood why.
It's not your "wide range of knowledge" but rather the risk profile of your employer. Some RFP's demand that the consultancy have 10k+ employees, 20+ years in business, and so on. Some of these requirements are government mandated, some process mandated, etc.
In other words, if you, with all your knowledge, were to strike out on your own, you would find yourself quite unable to bill at $400/hour, even if you were to be hired by the very same clients (which is not going to happen because they are paying the higher rate specifically so that they can get the low risk profile as per above).
In my experience, $400/hour at a large consultancy translates into ~$150/hour as a sole consultant, wide as your knowledge may be.
It's not your "wide range of knowledge" but rather the risk profile of your employer. Some RFP's demand that the consultancy have 10k+ employees, 20+ years in business, and so on. Some of these requirements are government mandated, some process mandated, etc.
In other words, if you, with all your knowledge, were to strike out on your own, you would find yourself quite unable to bill at $400/hour, even if you were to be hired by the very same clients (which is not going to happen because they are paying the higher rate specifically so that they can get the low risk profile as per above).
In my experience, $400/hour at a large consultancy translates into ~$150/hour as a sole consultant, wide as your knowledge may be.