L.W.
I don't know when you are planning your trip, but if it is in July or August, why not consider a family beach vacation to Northern Michigan and keep your money local? There are tons of beautiful sugar sand beaches with sand dunes and cute little towns from Saugatuck all the way up the west coast on Lake Michigan that can give you everything the east coast can. I am originally from Harbor Springs, so my bias is evident, but I really think there are a lot of really great places for families to go right here in our own state. Have fun planning wherever you go!