I saw your post on the Cabo wedding forum about the cost for guests. Perhaps it's because your wedding takes place during the "high" season? I think March is still considered high season; the closer to summer it gets, the lower the hotel prices there in Cabo should be since the weather gets quite hot. So that might be part of the reason why it's so expensive.
It looks like your guests are flying from the East Coast so if you want to look at other locations you might want to consider somewhere in the Caribbean -- like Puerto Rico, Dominican Republic, Jamaica. Maybe they'll have better packages since they're closer. I considered Puerto Rico prior to selecting Cabo as my DW site.
If you still would like to do Cabo, you might want to consider moving your wedding date to a time where it's more reasonable. I am doing a non-AI resort wedding so it's a bit anxiety-provoking at times but it's definitely cutting costs for both myself and my guests. Let me know if you have any questions and I'll see if I can be of more help to you!