Alright calm down.
I understand that these shotguns and such are expensive and the shells still expensive too.
It's not just price;
Indeed. I had the displeasure of buying some more recently. Shotguns are too large and too situational to drag around. A good rifle can be used in almost any situation.
Exactly. They're simply not reasonable in any way, shape, or form. They're over 2x more expensive than a carbine or assault rifle, and they cost more per-shot. Not to mention the recoil, usually low mag (or cassette) sizes, and the fact that it's a loving shotgun. In-fact, shotguns are rarely used in real combat, and police use special shells for them to break down doors. In-fact, "combat" shotguns are usually just modified hunting shotguns. Shotguns are so overplayed in media, people don't realize the only thing a shotgun was designed for was hunting animals (which is why we conceived rifled shotguns and shotgun slugs). FINALLY, there's the stereotype that shotguns are "close range only!" which is largely untrue:

Even birdshot isn't that inaccurate, and the effective range of shot is still pretty goddamn far.