Your Benelli is a nice weapon, I’ll agree on that. A Benelli like you described, used, typically starts off at about $1000 or more on the used gun market. A single spare barrel for a Benelli costs more than an entire Mossberg pump shotgun.
For general survival use and hunting, myself, I prefer a pump. It doesn’t automatically fling my empties out and away if I don’t want it too. I can also use various different types of ammo, including loads in blackpowder (a survival test that worked). They are also affordable enough that I can keep an identical spare shotgun around in case Davey Jones decides to borrow one.
Scalper’s prices is one reason I sold my last HK91 a while back, along with a ton of other stuff I had in storage. A prepper minded family in another boat sold their really nice Benelli a while back also into the panic and went with a couple of Mossbergs for the same reasons. These less expensive guns get done what needs to get done without risking and tying up a lot of resources that could wind up overboard, and could be used for something else (like body armor).
Mossberg basically has two critical components nowadays that are polymer: the trigger housing and the safety switch. I’ll respectfully disagree on the Mossberg parts issue with the trigger housing. For maybe the safety switch on the M500, I’ll agree somewhat. Swapping the safety switch on a M500 with the metal one from an M590A1 is a standard thing many M500 owners do, but still it’s not that common for even that to break.
The polymer trigger housing, the only major critical part that is polymer, actually breaks very rarely, this concerns both the tabs and the trigger guard itself. If it’s an issue, replace ahead of time the trigger guard on an M500 with the metal one from a Mossberg 590A1. Many people do this.
For a Mossberg Maverick 88 owner (slightly different trigger housing, tougher safety switch), if they are concerned, they can buy a spare polymer housing for not too much, the parts are readily available, but they’ll probably never need it. You are far more likely to need a new bead sight long before that ever happens, but that is true of almost any shotgun.
I and many others have beaten the piss out of Mossberg shotguns (people are less hesitant to abuse a $200 weapon) and they still kept functioning. No one I know of has ever had a polymer trigger housing fail. On the shotgun forums amongst Mossberg owners and on the Mossberg forums themselves, finding someone who has actually has such a parts failure is uncommon.
The M590A1 uses the same internal components as the M500 and it passed an Army test that involved the non-stop firing of 3000 rounds of full strength buckshot.
The parts for these weapons are commonly available because they are still in production, over 10 million have been sold, and they are still selling like hotcakes. Mossberg just had to add an additional 116,000 sq/ft of production area to meet up with demand at their Maverick plant.
One feature on the Ithaca I wouldn’t mind having is the downward ejection. It makes saving the fired hulls easier. The Ithaca isn’t a bad gun. Even the Mossberg 500 had a single charge bar like the Ithaca up until, IIRC, about 1970 when they went to two for extra strength and reliability.
The Model 12, while a fine weapon, went out of production 50 years ago, and they are not quite as simple in their design as newer models. Like the older Ithacas, the Model 12 could do slam fire.
Concerning the Chinese shotguns, the quality varies quite a bit. The Norinco made shotguns which H&R sells are pretty good. At the other end of the scale, soft parts, etc, are the ones sold by Century. The H&R guns come from the same factory that makes a version of the same shotgun (but with a 14″ barrel) for the Chinese military.