The DC discount will vary depending on the time of year(peak, or non-peak season).It will either be 10 or 20 percent off.
It just so happens that I will be getting there on June 2, so I know that the DC discount for the dates you mentioned will be 10%.
But even just 10% discount on the number of days you are staying will more than pay the membership charge, and the discounts you get on tickets, meals, and shopping will be gravy.
Good Luck
Griff
Fort Wildernes 85, 87, 92
Disney Village 97
Coranodo Springs 99
Fort Wilderness June 2-10 2001