I was contacted via email by a salesman at Logos who proposed I give them a list of resources and they would provide me the lowest price they could off the listed sales price.
Before I submitted anything, he sent me a large list of resources with reduced prices, but unfortunately, they were either all from reformed or from authors who are more liberal, which I avoid. I have enough of that stuff in my Portfolio LE package.
So I provided him two of the highly recommended resources from a pastor who is rather conservative and of the free grace side of the tracks and was told they were already at the lowest price online.
I have a hunch that the conservative materials are so much more in demand that they can afford to keep the prices higher as they have no problem selling them. The other stuff is hard to move and must be dropped in price. Economics tell a lot since one cannot argue obsolescence.