I personally wouldn't pay an annual fee to fish a specific place. On the other hand, by the time I calculate what I spend yearly on flyfishing gear, equipment, and supplies, not to mention all associated food, camping equipment, lodging, licenses for several states, and transportation costs, an annual fee of $500.00 is not comparatively outrageous.
There are too many public waters that are available. I might consider to pay for one day of C&R at Rockbridge one of these days.
Don