CTRL Z Command. Sorry for the PC terminology here. But It's essentially a "blam! go back!" button. Too many times have I accidentally dismantled my piece of powerful gear because I forget that once every blue moon I actually need to keep gear despite it being a terrible roll. When 90% of the gear we get is dismantled on muscle memory alone, sometimes mistakes happen. And it'd be nice to be able to undo a dismantle at the cost of the same amount of materials you gained. Another solution would just be to remove the power level grind completely. Then I wouldn't have to worry about forgetting to keep that cloak that happened to be Oh-so-much-more powerful because it had a higher number on it. Sick loot.