https://disneyworld.disney.go.com/sp...=Discount+Code

Save 25% on 4 day or longer tickets. Save more if you add park hopper and water park. For a family of 4, 8-day ticket + park hopper/water park at WDW would be almost $450 US off the package.

Note: the offer expires on May 20, 2017 but it is my understanding that the tickets remain valid until you use them -- after which they expire in 14 days time. You could buy now and use over the summer or next year.