Was the amount per person then? The books (per my link, I'm guessing they changed pricing seasonally so the article is also probably right) were ~$4.50 per adul

Was the amount per person then? The books (per my link, I'm guessing they changed pricing seasonally so the article is also probably right) were ~$4.50 per adult and included admission. If the number in the article was per person then the situation has gotten worse than it claimed, if it wasn't then it's better. (In any case, I missed that comment when I read the article the first time, you're right. Sorry!)