I had been thinking of doing this also to save on food/purchases, but someone told me the blackout dates include every Saturday from something like February through September! Since we'd be spending a bit more money to convert a parkhopper to the deluxe AP, plus would need to spend $30 to get into DL on the blackout Saturday, it's probably not going to be worth it for us (because we've already paid for air/hotel, and would likely not be coming back within a year.)
We'll get a bit of a break in some locations due to AAA membership...