Our family had the same issue and, unfortunately, I couldn't find a very cost effective solution, especially for our travel dates.
Since we'll be there for the actual 50th, the blackout dates for the cheaper AP made it impossible for us to make use of them. (The blackouts of the 16th and 17th are at the end of our trip, so we couldn't use park hoppers for those days and then upgrade, if that makes any sense.) We considered the Deluxe (is it the deluxe? whichever the one without blackouts is...), but the price seemed too high for us to justify it for a couple of extra partial days.
The 6 day hoppers we looked at were $219, and I couldn't find a discount anywhere - not Disney Visa, not DVC, not AAA. We went for the 5 day hoppers (paid $164 through a mousesavers link, but disney.com has a discounted rate of $169 as well). The $50 difference seemed pretty substantial to me, and if we have to bite the bullet and purchase additional day passes, then so be it.
The only other thing I heard was the $129 5 day hoppers available at World of Disney in NYC. The $40 difference from the already discounted price makes it cost effective to buy an additional 2 day pass, separate from your regular hopper.
Good luck with whatever you decide, and if you find a better answer, please post!!!
Just remember - BEWARE OF BLACKOUTS!!