Bukkit

What is the enhancement in mind? How should it look and feel?
I think that the bast way this plugin can work is:
Shift+Placing the itemframe.
then it will ask you to put your item inside of it, after you place your item you want to sell,
the command line will ask you "How much units you want to sell?"
and then simply type "1"
Then "Type the price for &31 item"
and then simply type "70"
"Select a storage chest"
At this point you just enter a chest and place your sellable item inside of it.

Shift+Placing itemframe "You just started creating a shop!"
*Placing diamond in the item frame*
"For how much you want to sell &3 1 diamond?"
"70"
"Please select storage chest"
*Entering a chest*
"Your shop have been created!"

Now when someone want to buy, he right click on the itemframe.
"How much you want to buy?"
"10"
"Are you sure you want to buy &3 10 diamond for 700$ ?"
"Yes"
"You bought 10 diamonds for 700$"