I think this is already used in EQ but im not certain, anyway even if it is its a good idea.
Can we set up our own shops where you have a seperate button/command which opens up a bank style window with 20 slots or so, you place the items you wish to sell into this slot (and price them if you like, if no price is set then the buyer must negotiate with seller). Then somone comes along and presses D on you (not sure what D is used for, but any button is good) if you have your script turned on then you say something to them similar to the way npc shopkeepers do then they have a list of all the goods you are selling. They simply click what they want then press accept (unless it has no price).
Also make shopping robots and shopping stalls available in the general section of the nano dept, a stall is similar to a hologram and is just a table which is placed infront of the user, if the user moves too far away from it it will dissapear, the bot is just an enginer bot (or something nicer but im not very bothered) which has the name "<SHOPNAME> open for business at <PLACE>, this bot follows all the usual bot commands but the hunt command makes the bot wonder around rather than fight, every 10 minutes the bot will shout its name or maybe something you have programmed it to shout. Obviously these guys cannot be killed and cannot fight.
This would make selling things much easier and the people who stand around an awful lot could be put to some use.