Want a cheap 410 break-open single shot and I've found a couple that are both NIB. A Hatfield which is Turkey made and a Rossi that comes from Brazil.

The Hatfield's barrel is around 26", but I do want to cut down to around 19" for my purpose. Walnut furniture, ventilated rib, trigger guard slide rearward break-open design(don't know how well this will hold up over time), receiver made of 7075 alloy, and a few videos of modifications some people do to them and of course the cost of just over $100.
 Also, seems to have a few components available from company like firing pins/springs/stocks/barrels(no 18" lengths though) for replacement parts.
This while being cheaper, is designed and input from same man, Tom Hatfield who made the, what are now quite expensive Hatfields from years past, but is now made by Turkey manufacture Huglu, that many of today's guns come from.

The Rossi is not the Tuffy, but is the 18" barreled youth model, but with adult length plastic stock, as I compared length with a full size model of 410ga. No ventilated rib, but what I think is a better break-open action using a push down metal tab design.
 Price higher at $140 from local shop. Doesn't seems to have much available for parts replacement that I can find, and not much for videos for mods, but more of reviews.

I have the Rossi.
I recommend it...
Very solid for the money.

Well my Rossi sucks ball bag.
The extractor cut is well up on the brass, 1\4" or so, and some brands exude into that cut.
Then they won't extract.
It really only needed just the rim but Rossi sees fit to extend that extractor way up the chamber.
No reason for that.

Sorry about that extractor, meistermash.

This was something I was also thinking of in that the Rossi has automatic ejection after opening, while the Hatfield is manual shell withdrawl.

Can't say a stockpile, but about 300rds of couple manufacturer's so far. Some AA 2-1/2" inchers and some Winchester 3".

Honestly, I would cruise local gunshops, pawnshops and gunshows until you find a used H&R single-shot .410 in good condition. You can usually find them relatively easily for ~$100 (more or less depending on condition and the seller). A simple, solid design that just works and is almost impossible to wear-out.

I have this whole crazy ‘ting for .410 and the H&R is my favorite.

I second the suggestion of an H&R.
I'm not sure about finding them easy or cheap.
It took my a while to turn up a 20ga, after turning my nose down on a better one.

NEF/H&R I will third. You used to be able to find them for under $100 but if you secured one under $200 tomorrow that'd be a deal. There's a few on gun broker.

Thanks guys, I'd love to get ahold of a NEF or H&R, but the ones I've seen around my area are going for rape prices of at least $250 and up.

These fudds love their old single shots, no matter if in rifle/pistol or shotgun and I guess I'll be joining them when I make my mind up.

I won't do online auctions either. I want to see/hold in hand to know what I'm actually getting. I don't trust people nowadays with guns and what they say about them online.

The last single shot break-open shotgun I had was when I was a kid. It was an Ithaca Super-Single Model 66 in 20ga. Loved that shotgun until my younger brother sold or traded it for drugs when I went off to AF basic in '73.

As luck would have it, today I picked up a h&r topper 158 12ga in ok shape for $80.
Was the best deal at this particular gun show that I saw.
36" barrel clean.
It is as old as I am.

I have a turkish RIA with the sliding trigger guard. Plastic, black painted metal.

It works. It seems to pattern straight. Points well enough for a gun three sizes too small for me. Worth the $90 for sure.

It did come with a pretty short, I think 18”bbl. Chances are they’re the same, so the part is out there.

I wouldn’t feel bad about cutting one down, but having it done would cost you more than the gun.

Haven’t shot any slugs, but I appreciate the two position rear notch. I assume it’s a 50 and 100.

The short barrel puts it in the noise territory of high brass 12ga out of a 26”.

The folding feature is nice for backpack or whatever. I’d look for a plug of some kind to keep debris out if you’re going to do that a lot.