No discounts on park hoppers for DVC.
The best price I have gotten is through Mousesavers newsletter link for Ticketmania. We bought 10 day hopper plus passes for our kids and son-in-laws for $358 (all taxes and shipping included). Since the kids are not residents of our household, we couldn't get annual pass discounts for them so we bought the next best deal we could find.
If you pick up passes from Ticketmania at their office in Orlando I think they will throw in something extra (they used to anyways).
Or how about AAA? I know they used to offer discounts on passes.
Good luck!