shift + klick instant sell would be imo better.
I remember long time ago asking for this, but i also remember the dev really focused on the resale window ("but you miss the resale window.....") and without understanding it.
I fully agree with you and i add some detail about what you said.
If I want to mass sell junks, i know *in advance* i'm not going to use the resale option, so i don't need to look at the resale window at all. It's my choice to press shift or not.
Same way to use ctrl *in advence* if i want to resale without changing the actual margin i have setup. If I want to make any change I just don't press they shift or ctrl to bring the resale window opened.
By the way, the shift and ctrl keys already works this way, but only after the resale window is opened so u need to press <return> each time. without mouse (ie: click item - shift - return and so on).
Shift and ctrl working as u said would really be a big improvement to the UI if the devs understand the logic.