Before booking our non-AI that we are doing in November, I really did a lot of research. I found the cost to be approx. the same comparing a package from Toronto (hometown) and the flight and hotel separately. But, we ended up booking from Buffalo (lucky as it is only an hour drive for us) for just over $300 each. And then got a Living Social deal at Country Country and now going non-AI is going to be considerably cheaper for us. And the deal included Breakfast and Dinner, however we can afford to skip the dinners when we want because they were virtually free. We did our last AI 2 years ago and said we would never do it again. Just not our style anymore.
Check out Living Social and Group On as there are lots of deals to Negril there.
Good luck!