That is sad that Elizabeth is already booked. Her work is simply amazing. And yes, Del Sol is pricey, but they aer worth it if it's in your budget.
Now, if that's not in your budget, have you thought about bringing down your own photographer? You can always find a photographer locally who is willing to go down, or there are a ton of wonderful options on this website. if you think about it, the price might be around the same. I paid $2500 to fly my photographer down (that included his fee, and all travel and accomodations). I paid for 4 nights at our hotel and I got 3 full days of coverage and all of the images on a disc. So it was an AMAZING deal. Perhaps it'd be something you're willing to look into.
As for the room discounts, do you already have a travel agent? If not, the ones on this forum are amazing because they specialize in, and in most cases had their own, destination wedding.