Surprised this thread hasn't taken off in the current climate, perhaps people don't want to display their income!
A friend of mine gets £20/hr teaching PPL with £200/week retainer, another gets no retainer and £25/hr. They are in opposite ends of the country and get 40-50hrs on a decent month.
Anyone offering to work for free at the expense of people who do it for a living should take a long hard look at themselves.