Typically it is $4 for an adult and $2 for the children. Here is the information from allears.net:
Recently, Walt Disney World began charging a premium on certain meals and dining experiences during peak seasons. Such seasonal pricing will be implemented at the following dining locations during peak seasons:
-- 1900 Park Fare
-- Akershus
-- Biergarten
-- Boma
-- Cape May Cafe
-- Chef Mickey's
-- Cinderella's Royal Table
-- Crystal Palace
-- Garden Grill
-- Hollywood and Vine
-- Liberty Tree Tavern (dinner only)
-- 'Ohana
-- Trails End
-- Tusker House
Upcoming peak times that will see the seasonal price increases are:
November 22 - November 29, 2008
December 16, 2008 - January 3, 2009
April 5 - April 18, 2009
May 24 - July 11, 2009