KCritter lucked out!!!
DVC membership DOES NOT entitle you to a discount on Park Hoppers, although many here (including myself) think it should. So I would not go to your local Disney Store expecting the discount.
The price is the same at Disney Store as it is at OKW. You CAN get a discount with the Disney Club card if you belong to that (you get the discount at both DS and OKW).
I personally would get the Hopper at OKW and have them put it on your room key. Then you have your hopper, charges, and key all on ONE card.
If you have unused days, keep the card. Then on your next vacation, take the card with you and when you check in have them transfer the unused hopper and plus days to your new key card.
Whatever you decide, I hope you have a GREAT first trip home!!!!!