I have recently read in server updates, that ability to control items by faction and level has been added to vendor inventory.
I would like to propose some more additions to that: ability for merchant to occasionally offer small quantities of rare items.
This would require 3 extra fields in DB:
-minq
-maxq
-timer (in min)
For example you would have a merchant who can occasionally offer Spider Silk for sale, which is not normally sold by vendors. You set minq to 0, maxq to 10, and timer to 2 hours.
Every 2 hours the timer will be checked, RND run, and between 0 and 10 spider silks added to that vendor inventory.
This could go long way for future customization depth, letting merchants to occasionally offer rare weapons, armor, and craft/quest items for sale