Mm not quite player shops then but

[LTA]

Well if you dont want to give players shops how about a barzar system like FFXI.

Make a section of your inv where you can place items, players can then right click you and select say view wares once they have viewed them they can decide to buy or leave.

Let the play set the price of each in some mini control window for the slot or for each item ... i dunno for multiples the same but i think if players dont have to spam and can sit afk with there bazar active it works to much the same effect, could even add a little icon in the title name somewhere that shows who is selling and who aint.

I think make something similiar to the ffxi player bazars is a little more feasable than whole stores....

buit scrappy on the idea but i just seen it when i was running my char for the last time

[Zeninja]

I suppose NPC vendors and shared appartements may also be a good starting point for developping an enhanced trade.

They're still available afaik, but not automated yet (requires GM action each time). Maybe they're able to add specific items (depending on their trackid) into a npc's list.