How much can money can a arboriculture make a year?

It depends what kind of job you have/had.

The amount of money you can make in a year is unlimited depending on what you can do.

It could be $100+ dollars a session, and with multiple sessions, that is a large sum of money.

average salary likely to be near 30k with the possibility in large upscale firms or management positions of making upwards of 50k

The money made by a broadcaster, much like the money made by an actor, a singer, or a painter, varies wildly. Great wealth or terrible poverty are equally possible.