IMHO their ad was a way to increase capital flowing to them. If 1000 people ordered and 20 of them cancelled their free income (return policy) nets them say $1K. Not bad for an item OOS.
It's a legal scam as they informed any buyers that there would be a restocking FEE, if order was cancelled. With thebuy's happening, who wouldn't jump on their deal, in stock or not. Hell my midway 22lr with plastic ammo can, will show up, eventually.