Their signs say you get 10% off the purchase of a case (10 boxes)...off REGULAR RETAIL PRICE. That being said, they've given me the extra 10% off more often than not.
However, walmart still has Federal 1oz loads in 12ga. for $4.67 per box....which about equals the estate shells at Joes, if you get the 10% discount. They are basically the same thing, as Estate is owned by federal.
Look behind the counter at walmart, not in the 100rnd value packs.
I also noticed my local walmart has remington and winchester 1 1/8oz "light trap" loads marked down from $7 to $5.00....look at the "clearance" rack.
I use the estate shells for new shooters, and for hand-thrown clays....but I wouldn't use 'em at distance. They are good, reliable plinking rounds and I would recommend them for that purpose......
This is coming from a guy who has shot over 2,000rnds of the stuff in the last 12-14months. A year ago, you could buy 'em for $3.99 regular price....or about $39 OTD with the 10% discount.

FWIW, the estate (and often remington) trap loads are on sale at joes pretty much weekly.