These stores cater to lovers of dying brands, especially candy
If you live in New York City or don't mind ordering online, Economy Candy has a cottage industry in candies from the 1950s - 1970s. You can stock up on Clove or Blackjack gum, Pop Rocks, Zaps, Mallo Cups, Sen-Sen and other things you haven't seen since you were a kid. Their mesmerizing shop on the Lower East Side also carries all the modern stuff, too--Pez, sour candy in gross shapes, and sugarless.
Vermont Country Store also serves the crowd that wishes some things never went away. They seem to focus more on granny type pajamas, mummus and chenille bedspreads, but they have room in their heart for a few dying products. When I made a pilgrimage to their store I was amazed to find brands that I'd never heard of that apparently someone is still aching to acquire. Do you crave Green Goddess Salad Dressing? Apparently someone does. Vermont Country Store reports that Kraft still makes it in limited quantities. You can have two bottle for $14.90. Want someone to say Gee, Your Hair Smells Terrific again? For $15 you can have the disco-era shampoo.
And then as any interstate traveler knows, there's Cracker Barrel. All the cheesy souvenirs you thought they stopped making are there. And so are Valomilks (which are rarer and more delicate than Mallo Cups) and other gems.
Now, they're regular stores, with no time travel ling abilities, so they still don't stock Hydrox or any of the brands that are really gone. (It's a shame that when big companies suffocate a brand like Hydrox, they make sure it's a quiet, slow death. If they'd just announce it, someone would surely swoop in, stock up, (hopefully freeze the stock), then make money on the brand-dispossessed.