I'm a level 40 Barb in Act II Nightmare. My experience so far is that I have salvaged all blue items and 90% of the rares, and been upgrading both the Blacksmith and Jeweller continuously. I've ended up having a couple of hundred Subtle Essence and perhaps a hundred Fallen Tooth, and absolutely nothing to use them on. I crafted perhaps 15-20 items, and use a couple of them, but it has certainly been expensive when compared to just buying the few items you need from the Auction House. I have also diligently saved all gems and combined them, only to find that I could buy much better gems on the Auction House for basically nothing. Combining gems and leveling the Jeweller appears not to be anywhere near worth it. What are your feelings? Skip the artisans completely, or do they have a practical purpose later on?