I empathize with your pain regarding 28 ga hulls. Winchester AA hulls have been very few and far between but those I have seen on shelves were a little cheaper than you've seen. The last were in the $17.99 range which still seems expensive.
I have regularly seen Federal loads in the $15-$17 range in many stores and that is what I would buy in current times. I use different hulls to differentiate between shot sizes and I load them with 7 1/2 shot. I typically get several reloads out of them before the crimp gets too brittle and begins to break or split. Some don't care for the Reifenhauser style hulls but in times of scarcity one makes do with what they can get.
