It depends on the individual. If somebody said to me "Is watching Man Utd worth the money?", my answer would be a resounding NO, but then I absolutely hate Man Utd. If you asked the Man Utd supporters the same question, the answer (leaving out the Glazer scenario) would be a resounding YES.
If you love Dolphins, Rays, tropical birds etc. etc. and you have the money, then the answer to your question will most probably be YES. I for one, am going to Discovery Cove next April (the previous times I've been to Orlando I couldn't afford it), and I'll be getting the video as well (do they do a DVD now?).