How about one dedicated area to vendors, all vendors? Instead of like 10 gates, make one mall where all players put their vendors..
Also.. i've seen this system working on other shard... There was a search for items in player vendors.
Example:
You type [vendor that brings up a menu where you type for example "fortune" ... The system will then search items in vendors and tells you names of vendors that sells anything related to what you searched and price of that item. So you can see that vendor XX is selling Cap of Fortune for 100k, vendor YY is selling Legs of Fortune for 120k etc. And whats even better, we can add a description to an item that vendor is selling. So if i would want to search for a ring with Lower Reagent Cost, the name of item is only "ring".. that will not help me much.. But if player would add there description "LRC 10%" .. and i would search for "LRC" ... This system would then show me which vendor is selling this....
Basically, now we have to run and open all vendors every day to see if someone added something new. It would also help players as some kind of a price check. You could just search an item and look for average price that players is selling it for.
Just an idea =) I played a shard that had this feature and i loved it. Im not sure how hard it is to make this work =)