I just did it last month with my 5 year old birthday girl. Yes, it is CRAZY expensive, but it was her birthday, and she LOVED it.

Here is an excerpt from my trip report.
The Perfectly Princess Tea Party at the Frand Floridian was just adorable. There were only about 20 girls there, mostly with their moms, all decked out in their Princess finery. Each girl was announced before entering the tea. She was given a tiara and showered with rose petals by our hostess, Rose Petal. When they got to their seats, there was a My Disney Girl doll (similar to American Girl) dressed as Sleeping Beauty awaiting each little girl. They were all so excited! Then when they opened up their napkins, each girl found a charm bracelet. Ooooooh! They were given magic tea (apple juice) and the moms got real tea. Julia insisted on adding several lumps of sugar to hers! She had such fun having a real life tea party. The girls had little finger sandwiches cut in the shape of hearts and fruit to eat. Rose Petal told them the story of Sleeping Beauty and they all sang some songs. Then, all the girls gathered in the center, and Aurora finally made her appearance. The girls were all so happy! They all danced with her, and then she came by each table to talk with the girls individually while we had some cake. We were also given some scrapbooking materials to take home with us. Now, this tea was RIDICULOUSLY expensive, but Julia had the time of her life, and it was so sweet to see how truly excited she was. And it was her birthday, after all
Being announced and crowned by Rose Petal
Meeting her Sleeping Beauty doll
close up of the doll
Enjoying "magic tea"
Tea sandwiches
With Rose Petal
With Sleeping Beauty
Pictures of the tea party