I'd find something like this convenient. Some other things I'd like to see: - If I try to move a full bag into another, I'd like it if a prompt would pop up, "Move contents?". If I hit "Yes", it would move everything in the bag I'm moving into the other bag, up to capacity limits. - I'd really like to be able to right click on an item in inventory and mark it Not for Sale. On occasion I've accidentally sold something I meant to keep, and if I could have marked it when I was thinking about keeping it I could have saved myself... from myself.
Also would mitigate some of the futzing time trying to make sure I'm marking the right inventory item Not for Sale in the merchant window.