Mex made sure that his weapons belt was secure and headed outside to meet the new person.  The first thing he noticed was Iziz's chattering. He caught enough of the conversation to realize that they were trading.  That was a good sign.  Iziz was a coward, so the person had to be friendly, and they might be able to use a trader's wares.
When he rounded the corner, though, he noticed the the person was wearing a robe.  Mex slipped his lightsaber into his vest and walked over.  "So," he said, looking over the man's personal affects that he could still see.  "Two lightsabers an crystals to make more, plus you wear robes.  Are you a Jedi?"  He didn't remember seeing the man at the temple before, but that didn't mean he wasn't a Jedi.