Where in the world can I go where I can rent a shack on a beach and watch the fishermen come in every day with their local catch and then pick out the freshest, most pristine seafood and have it simply grilled in front of me for some small pittance of a sum?
Bonus points if the local specialty is something that is ungodly expensive in the west like lobster or sea urchin or scallops or tuna belly.
Maine is probably a good starting point.
Indonesia. When I lived in Aceh, we would go to the beach, pick out a fish from the fishermen coming in and have it grilled up on coconut husks. They’d set up a plastic table in the surf, we’d eat the fish with our toes in the water drinking beers. The whole thing cost $10.
The ocean.
badum tish
Goa, India.
Rented a room for 3 weeks with a nice local family for $1.00 a night. The house was a short walk to the beach. (Colva Beach was the name.)
There were cafes along the beach with magnificent sun sets serving great tasting seafood with large portions for about $2.00 a plate. I tipped the waiter the equivalent of .10 each meal and he always made sure I had the best table in the place on my return the next evening.
Just go in the “winter”. Day time temps are in the high 70’s and low 80’s with cool nights. Summers are impossibly hot day AND night.
Welp, I just spent over a week in Ocean City, Maryland, and that place isn’t it. 
I was hoping for just what you described, but it was miles upon miles of carny food, some pricey “all-you-can-eat-crab” of varying quality a few places with really good crabcakes or fat fried clams (tho you couldn’t tell beforehand), and some halfway decent oysters at halfway decent prices (plus some real, disgusting, duds). But no real gems or bargains.
Tianjin, China is pretty good. It’s not actually on the beach, but you can get to a beach from there if you really must.
They are famous for their seafood, which is really cheap and prepared in literally hundreds of different ways.
It’s also only 2 hours or so from Beijing, where you can get roasted duck and many other great foods, including reasonably priced seafood.
No place in the US is going to compete on price with places in the developing world.
How many people? $10 sounds expensive.
I’ve camped on islands in Panama where we bought pretty big fish from fishermen for a couple of bucks and grilled them up. There are lots of simple eating places along the coast where a whole fried fish meal will still cost you a few bucks. But even Panama is relatively expensive compared to other places.
Some bargains would be expected for local or regional things unavailable elsewhere like Maine lobster or maybe Atlantic cod.
I went to Maine last year and was told, ‘oh, they sell lobster rolls everywhere - just everywhere! Like they sell hot dogs everywhere, only, lobster rolls! They’re great!’ Well, yes, they were everywhere, and they were good, there were lobster roll carts and trucks just like hot dog carts and trucks where I live. But of course, $10-$15-$20 each. Lobster is not cheap, anywhere. I’ve heard lobster fisherman bring home so much for home eating that their kids complain, ‘oh, not lobster AGAIN, can’t we have hamburger?’ Maybe that’s a factor in the price!
For narrow specialties that are only found in developed countries, like Maine lobster, maybe, but I’m sure you can get spiny lobster much cheaper elsewhere. And Maine lobster even at it’s cheapest is going to be far more expensive than seafood where the cost of living is small. If you’re looking for seafood for “a pittance,” as the OP asks, you’re not going to start anywhere in the US or Europe.
Wherever the boats are coming in you can get some deals. The fisherman may have ‘culls’, fish that have been damaged in the nets, lobsters missing a claw, that kind of thing. The crew often can keep a few fish for their own consumption that they will readily sell. And some are simply dishonest and will pull good fish from the catch to sell so they can keep the cash for themselves. However, the going rates are going to match the local economy. So as **Colibri **says, with the exception of something like Maine lobsters that aren’t available everywhere in the world, you’ll pay the least where the local prices for everything are low.
Go north to Lewes. It’s not any cheaper, but there’s way less crowds and the quality of both the people and environs are significantly improved.
Four.The most expensive element is the beer.
More “locally” - Ensenada, Baja. Fresh off the boat fish tacos!
Fucking lobstermen stuffing their kids with lobster, those fucks, when we tourists could be eating $3 lobster rolls!
Haven’t been there for years, but the oysters in Chincoteague, Virginia, used to go for reasonable prices. Raw on the half-shell, fried, and in oyster fritters.
The thing about Virginia oysters is that that they’re not as highly prized for flavor as cold-water oysters from Massachusetts or Maine, and they’re not as cheap as Louisiana oysters, which you can get for ten bucks a dozen in New Orleans and slop up with your own personal mix of “oyster dope” (choose between ketchup, horseradish, lemon, vinegar, hot sauce, etc.)
Pretty much any southeast Asian coastal village, town, or city, in my experience. There’s always a fish market and usually something ‘all you can eat’. And you won’t find it cheaper anywhere.
(And now I am dreaming of yum talay! You can try to make it elsewhere, but if you’re not looking at an ocean view it is not gonna be so good!)
The key if you want US specialties is to go when the “Festival” happens. Pay to get in and then eat all day.
The really big ones like this might have carny prices: https://mudbugmadness.com/
You want the ones like this: https://pfdauxiliary1.wordpress.com/
I find that typing in the particular critter you want to eat, plus “Firehouse” and “Fundraiser” usually works.
If it includes beer, than that’s more reasonable. I assume that would bring the fish down to around $1 a person.
Rockport/Port Aransas Texas. We sat on the beach and bought blue and stone crabs, shrimp, and later in the day, tuna and red snapper right off the boats. $20 for a clothes basket full of blue crab was the best deal that we made.
It’s not the nicest beach around but it’s far from the tourist feel like Corpus or Padre Island.