Flying into Miami is probably much cheaper and there are plenty of dives between there and Key West. John Pennekamp in Key Largo is a must see, Sombrero reef in Marathon is pretty cool also. There are lots of big wrecks in the 100ft range but I am a novice diver so can’t go that deep yet. The 7 mile Hogfish Sandwich at Sunset Grille in Marathon next to the 7 mile bridge is awesome. The Conch Chowder at Willie T’s is excellent also. If you do like lavish, dinner at the Little Palm Island Resort is as good as it gets. It is VERY expensive but if you can spend the money and still enjoy yourself it is something to see. We just started going to the Keys a few years ago and love it. We have not had the best luck with weather but still had a great time every trip. Oh yea, if you want to see Key Deer go to Deer Key at sunrise, they are everywhere. I have not personally seen one any other time of the day but at sunrise I have found them every time.