One issue that’s been much-debated about the Artisans is how much it will cost to upgrade them, and what benefits those upgrades will bring. @Diablo shed a bit more light on that in a tweet today.
When I?m playing with my friends, will we each focus on a single artisan to level faster or will that not make a difference?—Limiate
It’ll probably help a bit to diversify artisan leveling among a group of friends. To start at least.—Diablo
The Blacksmith, Jeweler, and Mystic can each be trained up to the fifth level. At each level they come into the knowledge of more crafting recipes, and of course their wagons get prettier. (They also gain more recipes when you find them as monster drops and hand them over, and there may be Artisan level requirements to learn them; Alvl 4 required to learn/craft recipe X, for instance. Plus Artisans can be specialized in particular item types later in the game, which will enable them to learn more crafting recipes for particular types of items.)
We don’t know details about how many new recipes they’ll learn, or if them being higher level enables other abilities, or changes their prices, or increases the variety of items they sell, etc. But it seems fairly likely, since there should be incentives to training up an Artisan. Beyond just the prettier wagon.
In any event, it doesn’t sound like it’ll be ruinously expensive to upgrade them, based on today’s tweet. (The only known cost is for the second level of Blacksmith, and it was very cheap in gold/materials.) If the money saving issue will only be in the early going.. Which means we’ll all have three max level artisans on most of our characters, ultimately. You’ll still probably want to twink recipes to one particular character, though. So all of your high level weapon recipes are on your Barbarian, for instance. That would be easier than trying to remember which of your chars had that one cool rare recipe for the big axe?