Please remember, most people go into their planning session and build the "perfect" wedding with all the extras youcould imagine. When you get you're BEO (Banquet Event Order) and estimated budget, most people are sticker shocked. We weren't becuase we knew we had added in every little extra and gimmick we could have possibly wanted.
At this time, the MK photo shoot is $800.00. Disney rates increase at the resort hotels between 5%-10% a year. If you were to take whatever ball park you have now, and factor in the increase at around 7% for each year you wait, you would *probably* be at least ball park (+/- $5000 I would say).
You have to remember that there are so many other aspects of a wedding to consider that are not included in the Wishbook. From things at Disney to things not at Disney. You will have your hotel stay, dress, accessories, transportation to and from Disney, any expenses you are covering for your bridal party, food expenditures while there, hair and make-up, costs of purchasing clothing for any events surrounding the wedding (rehearsal, etc), nail appointments, teeth whitening, massages, dress steaming, park tickets, costs of any DIY details for the wedding, floral preseration, cost of changing you name on you SS card and licenses, etc. As you see, the list just builds. Do not overextend yourself on the Disney budget alone, becuase things just keep adding up!
Be totally honest with you EM as to your budget and what your willing to spend. They can and will give you your dream wedding on your budget if it is realistic estimate and you have realistic expectations. One of the other options, and I have heard nothign but rave reviews on this board, is a Swan/Dolphin wedding. JustMarry.com seems to be the planner of choice. I have noticed how much less expensive they are. Another budget-conscious thing to look into is using vendors outside of Disney to get what you need and what- florists, photography, videography, etc.