When I want to sell something for 50 gc, I practically have to click 49 times because if I try to set the bar to 50, I'd have to drag the mouse precisely 0,00001 cms (or set mouse sensitivity to the minimum) before I even tried.
So perhaps instead of a scroll bar, there could be several up-down buttons that add/subtract 1, 10, 100 and 1000 gcs at one click?