I would be quite the purveyor. My wares would not necessarily appear to be anything of particular merit; however, they would be the most likely to progress the storyline by allowing the characters to access new or strange parts of their world. A ring that belongs in a dragon's horde, a diadem stolen from a goddess' personal wardrobe or a mace that is capable of shattering the very fabric of reality. It would not appear to be a fancy shop nor even a well maintained shop. But it would hold a number of fabulous ware  and quite a dangerous place for any curious kender.