$379 is $162 less than MSRP.
"...My local Walmart..." Yep. Wally World gets to tell the manufactures what they will pay as their 'dealer wholesale price'. No question of credit terms either. They can pay whenever they feel like it. Vs a small shop that may or may not even get credit terms and is on COD. Or, if they're lucky and have established good credit, get 30 days.
Wally World can buy a whole year's worth of a factory's production if they want to as well. And get it.
"...did the same thing with coffee..." Coffee, next to crude oil, is the world's most hotly traded commodity.
"...some fine but neglected calibers fall into oblivion..." Most of 'em are the answer to an unasked question in the first place. Nothing to do with negligence.