This excursion looks - on its face, at least - right up our alley. The fee is $369 for four people, but you can bring as many as six "for an additional fee". However, the DCL site does not list what that additional fee is. $369 for 4 people breaks down to about $92 per person. Is that the approximate "additional fee" for each additional guest? So, ~$185 extra for guests 5 & 6? Please and thank you!