Why not consider Universal tickets rather than Disney.
Universal tend to undercut Disney prices to encourage people to use their parks rather than Disney.
Universal have 2 great parks, Universal Studios and Islands of Adventure which are as good as anythng Disney have.
They also have 2 "partner" parks which is Wet and Wild (water park) and Sea World (sea animals plus some theme park rides) which are both excellent.
You can by a joint ticket for the two universal parks and the 2 partners parks for less than the price of Disney tickets.
I think you could still have a great holiday just going to these parks (and maybe just one or two Disney parks).
More about these Universal flex tickets here
http://www.universalorlando.com/tickets/orland o-flexticket.html