Xcaret, Xel-Ha, Boatswain's, Dunn River Falls

[Ravenne]

Those of you who have been to Xcaret, Xel-Ha, Boatswain's, and Dunn River Falls, do you have any advice on what's available for purchase there? I'm trying to plan out how much money to take with us if we end up doing those excursions. I know lunch is included on most if not all of those excursions, so I'm not too worried about that, but what else should I plan on having money on hand for? Souvenirs, of course. Do they push things like photo packages and opportunities at those locations? Anything that is a "must do" but costs extra? Anything that we should definitely check out, consider buying, a special treat, or something of the sort that's not included in the excursions? Should we consider bringing water, or buying bottled water at either Xcaret or Xel-Ha? I know about not drinking the tap water in Mexico, what other tips or advice do you have along those lines? What else in terms of food (or anything else) to avoid?

Thanks