I used to have one. Not a store, just an old house (with accompanying garage and shed) packed wall-to-wall, floor-to-ceiling with the best of 20th century American pop culture relics--mainly, blessed comics! The house was owned by a weird looking old duck named Karl Melton. He looked a little like Cain from DC's The House of Mystery; bushy, pointed eyebrows, Van Dyke beard, childlike twinkle in his otherwise ancient eyes. He wore loud Hawaiian shirts and lots of rhinestone jewelry. A real character, ya understand, who had obviously never married, for he hoarded books, comics, toys, records, cars...you name it. I guess he used to work for a magazine distribution company for years, and always kept two copies of every comic he ever moved--thus, the incredible collection.
He had everything. Since the time I was 13 (or so) till my early 30s, I often swung by his house (he always had a 'garage sale' sign on his lawn) to plunge into his piles of comics and purchase some treasures. Man, he had boxes upon boxes of the stuff--you had to dig and dig though walls and seas of long boxes, flipping through so many stacks yer head would swim. You'd come out of his garage reeking of aged newsprint (is there a better smell on earth? No.) with a handful of awesome books--Tomb of Dracula, House of Mystery, Creepy, The Witching Hour, Brother Voodoo, Thongor of Lost Lemuria, Turok, Son of Stone, Satanna, Red Sonja, etc., lots of great late sixties, early seventies stuff like that, two fer a buck. Inside the house proper you'd find pre-code horror (a bit more expensive), original hard-back Burroughs Mars books, dozens of sleazy 50s Ace paperbacks, original Elvis Sun Records 45s...just too many awesome things to mention. And if I couldn't afford the more expensive stuff, why, ol Karl had no problem lending certain items out (to me, at least).
American Pickers woulda had a field day with this place.
Alas, Karl is no longer with us. The house still stands, but that mammoth treasure trove has long since been sold off. It's a shame, because you just don't find places like that anymore. I'm currently writing a nostalgic horror novel based on old Karl and his 'house of mystery', and plan on dedicating it to him. I miss the old goat.