This reminds me of former NFL great and Monday Night Football announcer Frank Gifford. At one time, he charged $10,000 per corporate appearance. The grind was wearing him down, so he doubled his rate to reduce volume. Funny thing happened though, the higher rate made him more desirable to corporate program directors and his demand actually increased.
I wonder how applicable this phenomenon is here. You could easily become known as the "ie6 web design experts" who corporate drones turn to first. Sure, you'd make tons of money, but is that what you really want?
[EDIT: Lots of us are constantly dealing with the trade-off between whoring ourselves out for high paying shit work and doing what we really want. Just sayin'.]