What do you buy from player vendors on a regular basis?

[Fender]

I have a smithy vendor and ill have dp weapons up there when I can gm my poisoning. With that covered, I have another vendor to place and I want to know what people what the most. Before poisoning is done, my alchemy should gm, then its tailoring and lastly, bowcrafting. I want to stock only things that sell and avoid things that will sit on the vendor for weeks.

I would appreciate any input I can get to help me decide on what to stock.

[nightshark]

regs, kegs, weapons, runebooks, bandages if they are cheaper than the NPC shop

new players obviously would be looking for full spellbooks. there is a demand for filled runebooks, but not high, to my knowledge.

those are about the only reasons i would visit a player vending area