I am struggling with this a little too however it seems that some places are cheaper than others. I am trying to chose between the Barcelo Maya Colonial and the Grand Pallidium Colonial. It seems from what I can gather that any guestlist over 11 at Barcelo will force you into a private function but 20 people are covered for the meal and it is 24USD for every one over 20. For the Grand Pallidium however they will accommodate up to 40 in an a la carte but if you go over 40 you will pay 50-60USD for every guest over 8. As you can see it seems to vary quite a bit. So I would be really interested to see what others say about large groups.
What resort are you being married at?