Try the Dolphin or Swan, depending on the time of year, standard room run from $179 to $250.00+ a night, if you become a Starwood Resort member, your rate may be lower however, these hotels charge a resort fee, I think it's $18.00 a day; and $12.00 per day parking fee (this may have increased). They also charge an occidental fee in the amount of $100.00. BUT... you will be within walking distance to Epcot and Hollywood Studios and you have the option of using the Friendship boats. I personally prefer the Swan, but in my opinion the Dolphin is more kid-friendly. Keep in mind: Dolphin/Swan are NOT Disney owned hotels.
Disney's Beach Club, Boardwalk, and Yacht Club resorts are mostly always over $250.00 a night. I think the cheapest I got Yacht Club for once was $261.00 but that is very rare!
Caribbean Beach is the closest moderate to Epcot, but only via bus.