^I was just going to say the same thing. For English lessons (at least, H/J) $50-70 is pretty average.
Honestly, it depends. What is your skill level like, and what kind of experience do you have? What I have noticed, is the more "reputable" the trainer--or, maybe "high level" is a better way of putting it--the less likely they are to offer any sort of work in exchange for lessons. Of course, these trainers are also generally less likely to have lesson horses. At least, from what I have seen.
The sensitivity of the internet baffles me.