The quickest way to get estimated prices is to go to http://www.allseastravel.com and check on the dates and type of cruise. I don't think DCL has any cabins that sleep 6 so you'll need 2 connecting cabins so price two cabins with 3 people in each. One will be a little cheaper because DCL only charges port charges for kids under 3 but I think you have to talk to a representative to get that type of estimate.
The website can give you a quick "down and dirty" estimate.
The ages of your kids are perfect for a Disney cruise.
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