Listing an item at the wrong price is one thing. Like the reference to advertising a $1,500 gun for $15 on the EE. Of course you or anyone else doesn't have to stick to the advertised price. It all changes legally once the transaction is made, if the seller took the $15 dollars he is obligated by law to complete the contract and provide the item. It doesn't matter if you place your financial transaction security on software either, that was your choice, not the buyers.
I agree it's silly to attempt to profit from another's mistake, but the law is quite clear on this type of situation. Cabelas was legally obligated to provide the goods for the $$ they accepted for the goods. Their disclaimer has nothing to do with the transaction at that point, it doesn't even claim to.