Woot!
BTW, another small addition, a small feature that I call "Merchant Greed Factor", could be represented as a numerical field somehow attached to an individual vendor npc (maybe in npc_types table?)
What it does it sets up an additional % price penalty for goods sold/bought, which goes on top of prices modified by your CHA/faction
Essentially this allows you to have 2 different merchants on same faction, one of which will be set at default price setting, while another could be selling at additional +20% greed mark (his prices will be +20% more, and he will buy your items at -20%)
This could be used for example to distinguish between city and country side merchants who otherwise share the same faction - country side merchant would offer you prices at greed penalty so if you want to get the best price you would have to go to the city.
Alternatively you could set up traders square, where there would be 2 merchants who sell identical crafting supply items, but only one of them would spawn at a time, and one could have higher prices, while another would have lower prices etc, and they would switch places like every couple hours.
Of course you could also emulate this with just having them on 2 different factions, one of which likes you less than the other, but then you run into multiple issues like faction maxing out with both groups, or having them faction fixed for all races/classes to prevent faction maxing etc, which eliminates a need to work up a faction at all to buy/sell as say evil race in good city etc.
I think this could be a useful feature