At ML 3 Cannith Crafted weapons do 1d6 + 1d6; at ML 4, they do 2d6 + 2d6*- huge diff at that level. I'd
strongly suggest waiting for the latter (ML 4), and just using the Nicked Repeating Crossbow from the Marketplace Sharn Chain (ML 2, 2d6+3, +2% doubleshot) until then, ample for any QL 1-2 quests.
(* or 2d6 + 2d10 for Unnatural Bane, if you're a weapon swapper for undead/monstrous humanoid quests)
o ML 2:
https://ddowiki.com/page/Item:Nicked_Repeating_Light_Crossbow
Even the default Ember Repeater does the job just fine, and almost(?) any ML 1 Repeater you find will be an improvement over that - all Repeaters are OP for Level 1-2 quests, even without any Enhancement damage boosts.