Makes me wonder why our .410-bore and 28-gauge skeet loads are so damn expensive these days.
An ad from the March 1978 issue of
The American Shotgunner - "Offical Publication of The American Association of Shotgunning"
(BTW, Bill's was a high-volume discounter.)

Plugging some of those numbers into an inflation calculator is pretty revealing.
Lead in 2006 dollars would have been $30.78 a bag.
In case lots, 12 ga. AA's would be $9.89 a box, and 28's would cost $10.82 a box today!

The BIG TWO hadn't yet discovered that they could actually charge more for less, and AA .410's could be had for
only $8.96 a box. :?
Even into the late 70’s premium factory .410’s were on par or slightly
cheaper than premium 12’s and 20’s. Sometime in the 80’s the manufacturers realized that they could charge more (later
MUCH more) for less, and we’d pay it just to get their precious little sub-gauge empties. Further proof that the retail price of shells isn’t determined as much by the cost of the components as it is by whatever the limited market will bear.
*Sigh* So much for the good 'ol days.