I love the idea, and I very much so wish that this could happen, but this might not be possible do to the /setwarp. This is because there is already a perk that you can get from the perk chest that uses the /setwarp command. And make a warp for a shop area? They would have to make a fairly large area big enough for players to have shops, and also disable/enable block break/placement in certain areas. What I would replace, though, is make a command that uses /playershops that brings up a list of all player shops that you can filter using name/most used. That way you can store items in it to sell to other players that you can set a price on.