lxs The Curves view should be helpful for your purposes. In the Curves view, the Y axis represents relative changes rather than absolute values. This is useful, for example, when you want to match the shape of a curve (the progression of the change) between keys where the scale changes positively from 1 to 2 and keys where the scale changes negatively from 1 to 0.5.
The following video demonstrates how to use the Curves view to match curves. After adjusting a handle in the Graph view, select the keys whose curves you want to align, then click the handle of the key you want to use as a reference in the Curves view. This will align the curves of the selected keys:
Of course, you can also select the keys you want to match from the beginning and then adjust the handles directly in the Curves view.
