Yo Issues!
Watch Paris on a map, then see then draw a small circle in the middle of the city... this small "village" is called "Châtelet", also called "Châtelet - Les Halles", "Les Halles" because there is a vilage under this place, underground.
Through Chatelet u gonna find a lot of record stores, hip hop and electro, but don't lose time cause they are expensive. Walk through the streets u gonna find a lot. Then u gonna find second hand record stores, here u go.
>>> The train is called the "metro", go the station "Les Halles", then you are in "Les Halles", so three floors under "Châtelet", take the escalator, climb till u are in Châtelet. Then walk to your right, until u see a small place, with a fountain, after this place, take the first street on the left, then search and u gonna find a second hand record store... U can go on that way after diggin that store, but just one street cause after u in the gay distict...
In "Les Halles", there is a "fnac" at floor -2... the fnacs are the french Virgin Megastore, there are Virgin Megastores too in Paris... go to the fnac, there are a lot of things, but no oldies, reissues only. There a fnacs all over Paris.
Also, u can go the ghetto way. On a Saturday, Sunday , or Monday. Take the metro 4 to the Terminus "Porte de Clignancourt", then follow the people, u gonna cross 2 or 3 streets and u will be in the "Marché de Clignancourt". This is an very large outdoor market. People's used to go there to get less expensive clothes. The 15 first minutes u gonna walk u will only see clothes and shoes stores, then u gonna hear music and u gonna see the dancehall and hip hop stores, the go on walking and u will be in the second hand part of it, here are the records. Get your eyes open: Clignancourt is a crowd place, beware or pickpockets.