I understand that the present system(s) of production are probably in place to assure that there is a community that works together and, at times, competes. That's part of the game. However, when no one is around, this can stall people from pursuing whatever it is that they want to pursue - be it a quest, for example, to learn how to make sharp & pointy things. The sharp & pointy things require raw materials, and unless someone is standing right there with the materials on hand it simply doesn't work.
So a quest or an aspiration may be shelved.
I also realize that this might be something that is already planned and is simply not implemented yet. But I'll ask anyway.
NPCs who carry raw materials can (and should) charge exorbitant prices and have a limited supply - perhaps per day, or ideally by what they've been sold by other players. In that way, flow for a character isn't necessarily stalled. It's just changed until a cheaper supply has been found - something which is economically feasible to the player. After all, when mining ore (as an example), if no buyer is around one can still sell to an NPC. Why not buy as well?
Just a thought.