If the market-clearing price that their competitors are selling it for is $50, they’ll sell it for around $50 or they won’t sell it.

You two are saying the same thing. If they won't sell due to an uncompetitively high price, then they'll have overstock. Then they'll be "forced to" sell lower.

I’m saying they’ll do it even if they’re just normally (or even partially) stocked with material. They know their customers are cross-shopping them with other stores, they need to be competitive, and they don’t want to lose the rest of the order lines nor train customers that they’re not competitively priced.

I consider that covered under 'and such' but, it's not so simple.

There's about four layers between the chainsaw and the consumer. So HD, Lowes, etc all exist at layer 4, sometimes 3 and 4. None of them are going to price cut below what they paid. Call it a gentleman's agreement, or common sense.

What you'll most likely see is buying from layer 3 at say, 50, and selling both 100 and 50 dollar wood together at 75.