A human with 50 solid years of varied work experience in his/her field should be Exp20. They should be rare to be sure. The village smith... Exp2-15, depending on age and how interesting a life this village leads. There are a multitude of ways to gain xp without resorting to hunting a killing the evil weaklings of the forest. Another thread metioned that, for instance, every time an unscrupulous merchant overcharged for an item, they got xp. A very few points perhaps, but they do. I say, don't be stingy. The PCs are the special cases in a world filled with 99.9% NPCs. An Exp12 focusing on his/her apothacary could be a valuable resource. How many Exp3 merchants will have a few thousand gp sitting around waiting to buy a spare magic sword and armor that nobody wears from a PC party. These guys are going to be Exp merchants 14,15+ at least. They have to be. Craft: Anything can be done well by NPCs. Mithril Plate at 1st level? In the scenario described above technically yes. Realisticly, no and the DM should put the old foot down and say so.
I still say change the sp to gp and run with that.
I still say change the sp to gp and run with that.