Does not sound very fair at all...
But there is always a way around it... Just don't do it...
I'm sure there are other GPS approaches around that you can use.
Now what about if you land? Are you charged for the approach and landing or just the landing?
Or set a precedent and refuse to pay the bill sure you may end up in court but??? Get a group together and see what happens.
Reminds me of the NT Gov trying to make the Katherine Gorge a restricted area that you had to pay to use???