I don't think OP is suggesting that dealers shouldn't be trying to do this - of course they do. He's offering WF members a chance to get some negotiating leverage by knowing their buy price.
That's a very handy thing to know, because if you can find a car that's been sitting on the dealer's lot for a while, they'll often come quite close to buy price if you push hard enough, because it's taking up space.
Whoever is blathering on about expenses needs to learn the difference between marginal and fixed costs. In a buyer's market, as long as the marginals are covered, they'll often cut deals on low margins just to move inventory and free up working capital. It's why shops have seasonal sales ffs, instead of just waiting for their stock to move at full price.
+rep thank you
if you don't want to know dealer pricing, then GTFO of this thread