Expenses like food and excursions are the reason you take a vacation. No reason to fly all the way out there and then stay in your hotel to avoid paying $80 for a lift ticket or a snorkel trip. Hotels can vary, but overall you won't find very different prices for the same level of service.

I save on travel. I'm young and can manage reasonably well with red-eyes and sitting in coach for hours on end. Even if others can't, there's just so much more variability in the fares you'll find if you're willing to say, travel on Thursday instead of Friday, or at 11 AM instead of 7 AM, even if you want to stick with a favored airline.