Just thought I'd throw out a possible new idea for vendors, presets/recents.
The way it works is essentially, the vendor window records what items you last vended for buy/sell and saves them as a "recent" vend option, saving time for vendors experiencing disconnects, or a server maint/restart.
Presets are very similar, but they're mostly for the purpose of if a vend is accidentally closed somehow you can just select "Preset 1" and instantly re-open the same shop.
Comments are welcome, keep them positive.