Masterwork Goad
The Masterwork Goad is incorrectly classed as an item with a 1 to 5 gold piece value and shows up in the wrong loot tables.
I found one in a random pile of trash in the sewers underneath the slums district the other day, in an area with low spawns.
Vaasi Leather Satchel
The Vaasi Leather Satchel is a very useful item, but terribly overpriced for the service that it offers. One bag costs me almost 600gp.
That is almost 600gp more than normal item containers, such as the Large Crate or Briefcase, just to save 0.8lbs of carrying capacity?
Arrows / Bolt / Bullets
At times ammo incorrectly shows up as costing 0gp, but you will still be charged 1gp when you purchase it. Might just be a NWN bug.
In this case it was the Arrows, Bolt and Bullets ammo sold by Crawler down in The Drain, the merchant's reaction was unfavorable.
Nobles' Clothes
I noticed that the expensive clothes costing several hundred gp at the tailor shops in Vallaki and Port-A-Lucine are the exact same as 1gp clothes.
It would be a great addition if they provided a minor stat bonus to make them worth their value, perhaps a +1 Influence or +1 Appraise bonus?