While planning my wedding I found that prices were higher than I expected. We were also unable to get any pricing for Jan 2008 until June 2007. I think the point to remember is that the resort does not seemed impressed by you organizing a large group of people to come there, there is no real price break. FI and I have vacationed a lot always on a last minute deal about a month in advance to 5* resorts for great deals.
When you are booking your group wedding trip they don't really discount. The advantage of the group booking is that if the resort is full (and it happens) group members shouldn't be bumped to other resorts. If someone books on their own they run the risk of being bumped. Also, when we were booking last month they told us how many seats were left on the plane for Jan 2008 and it was pretty full. There is no guarantee that there will be room on flights or at the resort if people book on their own.
Ladies, regarding photographers I urge you to talk to wedding photogs you are interested in that work local to you. I got a recommendation from my travel agent that a local photog likes to travel. His work is great but he and his wife offer a special deal for off season destination weddings. They travel on the trip and you do not pay for the travel. You agree to purchase one of his higher end pkgs and he comes on the trip at their own cost. His albums are really unique, more like yearbooks or coffee table books, I am so excited. He is also coming to our reception for a few hours a month after the trip. It is more than we wanted to spend on photography, but there is really nothing I can compare prices with since he is travelling with us.