Actually the answer to that is no. All Faction vendors require Crucible marks for currency, though you could Rank them up completely in PvP. You at the very least need to participate in between 20 and 30 Crucible matches to be able to afford a legendary piece from a faction vendor. This isn't a bad idea anyway though as that's a lot of XP and loot chances along the way.
Seems like bad luck, until you realize how valuable "junk" purples can be for ascendant shards.... break that ish down
The class items don't require crucible marks, just glimmer. And you have to be level 20.