Barter area-select shows 0 items remaining

[Asgaroth22]

The barter stand interface always displays that there's 0 items left even though there are stockpiled items remaining within the selected area. By 'area' I mean the one created by Shift-right clicking a barter 'hand that takes'.
It's misleading potential customers.
It would also be nice if the tooltips on the hands mentioned that they have this shift-right click functionality.
And while you're at it, delete barter poles as they're redundant and a trap at this point.