Why do hearing specialist make more money on average than AuD?

I have been accepted into an Audiology program for the Fall 2012. However, I have been offered a paid apprenticeship with a hearing healthcare practice to become a licensed Hearing Specialist. In doing my research, I discovered that Hearing Specialists earn more on average, in many cases, much more that AuD's. How do I justify another 4 years in school when I could be practicing the same hearing healthcare within a few months, successfully helping patients resolve the same problems, and making more money?