Welcome to the forum! We have the same problem because we are getting married in Cabo June 2011. Luckily we are working with a wedding coordinator there. She agreed that this can be a problem when estimating costs. However, she estimated cost (for every vendor and site fee, etc) based on the increases from previous years...i.e. just a guess, but an educated guess. If you're working with a wedding planner, I suggest asking them what their experience with annual cost increases have been. If not, I would imagine there is a wedding coordinator or someone else at the hotel who you can ask. Sometimes I've found they are afraid to commit to a number, but if you just let them know you are simply looking for an estimate and will not hold them to anything. Just be sure to let your guests know that these rates are not guaranteed into the next year. Good luck!