Actually, for the next two days it can be cheaper to buy new 28-ga. AA shells than it would cost you to load them. Academy Sports sells new 28-ga. AAs for $89.90/flat (10 boxes) with free delivery, that's $8.90/box -- let's round it up to $9/box. Couple that cost with the $2.00 rebate per box from Winchester (expires 8/13/16) your cost is ~ $7/box. You shoot these shells and then you can sell the once-fired empties for the going rate of $.15/hull or $3.75/box. $7.00 minus $3.75 nets you out at $3.25 cost per box.
Now you can see that if your reloading costs are ~ $5/box you can realize $1.75/box savings by buying new.
I still reload 28-ga AAs. I wonder why?