I was there a couple weeks ago. I think it was $10. Definitely worth it if you haven't seen the falls.
If you visit Castle Crags SP first you pay 8 and the ticket gives you free entrance to Burney Falls.
Day use $10.00
Paid $10 for a day
We spent most of a day and it didn't cost anything that I can remember
I came in on the other side of falls,I don't know if I evaded a toll area or not. Don't let a few bucks stop you from this place, its beautiful.
Thanks! Your answer is awaiting moderation.