The prices given in the latest brochure for arrivals between 9th November 2007 and April 2008 are
Low Season - £638 (about $1295)
Mid Season - £736 (about $1495)
High Season - £864 (about $1755)
Children under 7 stay free until end of March
Children 7 to 11 years - £88 (about $180)
These prices include 3 nights accomadation, 4-day park tickets, breakfast and local taxes.
I hope that this gives you a little bit of help.