Nick Hornby began chapter 14 of his novel High Fidelity with:
Ever since I've had the shop, we've been trying to flog a record by a group called the Sid James Experience. Usually we get rid of stuff we can't shift - reduce it to 10p, or throw it away - but Barry loves this album (he's got two copies of his own, just in case sombody borrows one and fails to return it), and he says it's rare, that someday we'll make somebody very happy. It's become a bit of a joke, really. Regular customers ask after its health, and give it a friendly pat when they're browsing, and sometimes they bring the sleeve up to the counter as if they're going to buy it, and then they say 'Just Kidding!', and put it back where they found it.
Anyway, on Friday morning, this guy I've never seen before starts flicking through the 'British Pop S-Z section', lets out a gasp of amazement and rushes up to the counter...
Use the above as inspiration to write a story which begins in a second-hand store.