Hos, I think your analysis of those who use 2 1/2" shells might be correct but then you conflate that group with the entire shotgun world. Doubles chambered for 2 1/2 inch shells appeal to a relatively small group, yes. Those are the people who buy these guns, not the rest of the shotgunners who might use pumps or autoloaders, and those are the same people who determine the "value" of these guns. The market for guns chambered for 2 1/2-inch shells exists independent of the rest of the market. It's sort of irrelevant what the vast majority of shotgun owners shoot - they don't at the present time have an effect on the 2 1/2-inch market nor will they in future.
Also, I do not think (just my opinion) that 2 1/2-inch shells are exorbitantly priced - they are a just bit more than comparable quality 2 3/4-inch shells.
