B/X was the first version of D&D I played. One of my friends introduced me (he just had the basic set) and after a few months I somehow begged/cajoled my way into having my parents buy me the Expert set (I think it was also the only one I could find locally). We hobbled through playing along with a borrowed copy of the Basic set from the library. At least one summer someone in our group always had that set checked out (they had a rule on how many consecutive times a person could check something out, so we kept it in rotation). Eventually I got a Basic set of my own, but it was the Mentzer revision (BECMI). At the time, we couldn't determine any specific differences in the rules (we were 8 and didn't even understand words like "encumberance," so we ignored rules that we didn't understand).
We ended up mixing and matching books and adventures from B/X, BECMI, and AD&D because we were pretty much on our own and didn't have anyone telling us we were playing "wrong." There weren't any game stores around here then; I bought D&D books from playing like Ed Shock's Toys and Hobbys, KB Toys, and even Kroger. It was a special time.