I don't think the Blue Hole is worth a special trip, or worth the money, though some people seem to. Mostly it's just heavily marketed with those cool aerial photos. (I did it first time I was there on a liveaboard, since I was sitting on top of it anyway. Second time I was there on a liveaboard, I skipped it. Third time on a liveaboard, all the passengers voted against it.)
Most Blue Hole trips you will do 2 other dives in that area, which may be some of your best dives in Belize, but I'm still not sure it's worth the trip or money involved.
What is your dive experience? Aside from whether it is worth it, it's not something inexperienced divers should really do (even though many do.)